BASELINE: Update Chromium to 55.0.2883.105

And updates ninja to 1.7.2

Change-Id: I20d43c737f82764d857ada9a55586901b18b9243
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

1 files changed, 376 insertions, 264 deletions

diff --git a/chromium/base/bind_internal.h b/chromium/base/bind_internal.h
index c7d6c3b4adc..d16109e4243 100644
--- a/chromium/base/bind_internal.h
+++ b/chromium/base/bind_internal.h
@@ -18,10 +18,6 @@
 #include "base/tuple.h"
 #include "build/build_config.h"
 
-#if defined(OS_WIN)
-#include "base/bind_internal_win.h"
-#endif
-
 namespace base {
 namespace internal {
 
@@ -29,40 +25,80 @@ namespace internal {
 //
 //
 // CONCEPTS:
-//  Runnable -- A type (really a type class) that has a single Run() method
-//              and a RunType typedef that corresponds to the type of Run().
-//              A Runnable can declare that it should treated like a method
-//              call by including a typedef named IsMethod.  The value of
-//              this typedef is NOT inspected, only the existence.  When a
-//              Runnable declares itself a method, Bind() will enforce special
-//              refcounting + WeakPtr handling semantics for the first
-//              parameter which is expected to be an object.
-//  Functor -- A copyable type representing something that should be called.
-//             All function pointers, Callback<>, and Runnables are functors
-//             even if the invocation syntax differs.
+//  Functor -- A movable type representing something that should be called.
+//             All function pointers and Callback<> are functors even if the
+//             invocation syntax differs.
 //  RunType -- A function type (as opposed to function _pointer_ type) for
-//             a Run() function.  Usually just a convenience typedef.
+//             a Callback<>::Run().  Usually just a convenience typedef.
 //  (Bound)Args -- A set of types that stores the arguments.
 //
 // Types:
-//  RunnableAdapter<> -- Wraps the various "function" pointer types into an
-//                       object that adheres to the Runnable interface.
 //  ForceVoidReturn<> -- Helper class for translating function signatures to
 //                       equivalent forms with a "void" return type.
-//  FunctorTraits<> -- Type traits used determine the correct RunType and
-//                     RunnableType for a Functor.  This is where function
+//  FunctorTraits<> -- Type traits used to determine the correct RunType and
+//                     invocation manner for a Functor.  This is where function
 //                     signature adapters are applied.
-//  MakeRunnable<> -- Takes a Functor and returns an object in the Runnable
-//                    type class that represents the underlying Functor.
-//  InvokeHelper<> -- Take a Runnable + arguments and actully invokes it.
+//  InvokeHelper<> -- Take a Functor + arguments and actully invokes it.
 //                    Handle the differing syntaxes needed for WeakPtr<>
-//                    support, and for ignoring return values.  This is separate
-//                    from Invoker to avoid creating multiple version of
-//                    Invoker<>.
-//  Invoker<> -- Unwraps the curried parameters and executes the Runnable.
+//                    support.  This is separate from Invoker to avoid creating
+//                    multiple version of Invoker<>.
+//  Invoker<> -- Unwraps the curried parameters and executes the Functor.
 //  BindState<> -- Stores the curried parameters, and is the main entry point
-//                 into the Bind() system, doing most of the type resolution.
-//                 There are ARITY BindState types.
+//                 into the Bind() system.
+
+template <typename...>
+struct make_void {
+  using type = void;
+};
+
+// A clone of C++17 std::void_t.
+// Unlike the original version, we need |make_void| as a helper struct to avoid
+// a C++14 defect.
+// ref: http://en.cppreference.com/w/cpp/types/void_t
+// ref: http://open-std.org/JTC1/SC22/WG21/docs/cwg_defects.html#1558
+template <typename... Ts>
+using void_t = typename make_void<Ts...>::type;
+
+template <typename Callable,
+          typename Signature = decltype(&Callable::operator())>
+struct ExtractCallableRunTypeImpl;
+
+template <typename Callable, typename R, typename... Args>
+struct ExtractCallableRunTypeImpl<Callable, R(Callable::*)(Args...) const> {
+  using Type = R(Args...);
+};
+
+// Evaluated to RunType of the given callable type.
+// Example:
+//   auto f = [](int, char*) { return 0.1; };
+//   ExtractCallableRunType<decltype(f)>
+//   is evaluated to
+//   double(int, char*);
+template <typename Callable>
+using ExtractCallableRunType =
+    typename ExtractCallableRunTypeImpl<Callable>::Type;
+
+// IsConvertibleToRunType<Functor> is std::true_type if |Functor| has operator()
+// and convertible to the corresponding function pointer. Otherwise, it's
+// std::false_type.
+// Example:
+//   IsConvertibleToRunType<void(*)()>::value is false.
+//
+//   struct Foo {};
+//   IsConvertibleToRunType<void(Foo::*)()>::value is false.
+//
+//   auto f = []() {};
+//   IsConvertibleToRunType<decltype(f)>::value is true.
+//
+//   int i = 0;
+//   auto g = [i]() {};
+//   IsConvertibleToRunType<decltype(g)>::value is false.
+template <typename Functor, typename SFINAE = void>
+struct IsConvertibleToRunType : std::false_type {};
+
+template <typename Callable>
+struct IsConvertibleToRunType<Callable, void_t<decltype(&Callable::operator())>>
+    : std::is_convertible<Callable, ExtractCallableRunType<Callable>*> {};
 
 // HasRefCountedTypeAsRawPtr selects true_type when any of the |Args| is a raw
 // pointer to a RefCounted type.
@@ -80,239 +116,177 @@ struct HasRefCountedTypeAsRawPtr<T, Args...>
                        std::true_type,
                        HasRefCountedTypeAsRawPtr<Args...>>::type {};
 
-// BindsArrayToFirstArg selects true_type when |is_method| is true and the first
-// item of |Args| is an array type.
-// Implementation note: This non-specialized case handles !is_method case and
-// zero-arity case only.  Other cases should be handled by the specialization
-// below.
-template <bool is_method, typename... Args>
-struct BindsArrayToFirstArg : std::false_type {};
-
-template <typename T, typename... Args>
-struct BindsArrayToFirstArg<true, T, Args...>
-    : std::is_array<typename std::remove_reference<T>::type> {};
-
-// HasRefCountedParamAsRawPtr is the same to HasRefCountedTypeAsRawPtr except
-// when |is_method| is true HasRefCountedParamAsRawPtr skips the first argument.
-// Implementation note: This non-specialized case handles !is_method case and
-// zero-arity case only.  Other cases should be handled by the specialization
-// below.
-template <bool is_method, typename... Args>
-struct HasRefCountedParamAsRawPtr : HasRefCountedTypeAsRawPtr<Args...> {};
+// ForceVoidReturn<>
+//
+// Set of templates that support forcing the function return type to void.
+template <typename Sig>
+struct ForceVoidReturn;
 
-template <typename T, typename... Args>
-struct HasRefCountedParamAsRawPtr<true, T, Args...>
-    : HasRefCountedTypeAsRawPtr<Args...> {};
+template <typename R, typename... Args>
+struct ForceVoidReturn<R(Args...)> {
+  using RunType = void(Args...);
+};
 
-// RunnableAdapter<>
-//
-// The RunnableAdapter<> templates provide a uniform interface for invoking
-// a function pointer, method pointer, or const method pointer. The adapter
-// exposes a Run() method with an appropriate signature. Using this wrapper
-// allows for writing code that supports all three pointer types without
-// undue repetition.  Without it, a lot of code would need to be repeated 3
-// times.
-//
-// For method pointers and const method pointers the first argument to Run()
-// is considered to be the received of the method.  This is similar to STL's
-// mem_fun().
-//
-// This class also exposes a RunType typedef that is the function type of the
-// Run() function.
+// FunctorTraits<>
 //
-// If and only if the wrapper contains a method or const method pointer, an
-// IsMethod typedef is exposed.  The existence of this typedef (NOT the value)
-// marks that the wrapper should be considered a method wrapper.
+// See description at top of file.
+template <typename Functor, typename SFINAE = void>
+struct FunctorTraits;
 
+// For a callable type that is convertible to the corresponding function type.
+// This specialization is intended to allow binding captureless lambdas by
+// base::Bind(), based on the fact that captureless lambdas can be convertible
+// to the function type while capturing lambdas can't.
 template <typename Functor>
-class RunnableAdapter;
+struct FunctorTraits<
+    Functor,
+    typename std::enable_if<IsConvertibleToRunType<Functor>::value>::type> {
+  using RunType = ExtractCallableRunType<Functor>;
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = false;
 
-// Function.
+  template <typename... RunArgs>
+  static ExtractReturnType<RunType>
+  Invoke(const Functor& functor, RunArgs&&... args) {
+    return functor(std::forward<RunArgs>(args)...);
+  }
+};
+
+// For functions.
 template <typename R, typename... Args>
-class RunnableAdapter<R(*)(Args...)> {
- public:
-  // MSVC 2013 doesn't support Type Alias of function types.
-  // Revisit this after we update it to newer version.
-  typedef R RunType(Args...);
+struct FunctorTraits<R (*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
 
-  explicit RunnableAdapter(R(*function)(Args...))
-      : function_(function) {
+  template <typename... RunArgs>
+  static R Invoke(R (*function)(Args...), RunArgs&&... args) {
+    return function(std::forward<RunArgs>(args)...);
   }
+};
+
+#if defined(OS_WIN) && !defined(ARCH_CPU_X86_64)
+
+// For functions.
+template <typename R, typename... Args>
+struct FunctorTraits<R(__stdcall*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
 
   template <typename... RunArgs>
-  R Run(RunArgs&&... args) const {
-    return function_(std::forward<RunArgs>(args)...);
+  static R Invoke(R(__stdcall* function)(Args...), RunArgs&&... args) {
+    return function(std::forward<RunArgs>(args)...);
   }
-
- private:
-  R (*function_)(Args...);
 };
 
-// Method.
-template <typename R, typename T, typename... Args>
-class RunnableAdapter<R(T::*)(Args...)> {
- public:
-  // MSVC 2013 doesn't support Type Alias of function types.
-  // Revisit this after we update it to newer version.
-  typedef R RunType(T*, Args...);
-  using IsMethod = std::true_type;
+// For functions.
+template <typename R, typename... Args>
+struct FunctorTraits<R(__fastcall*)(Args...)> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
 
-  explicit RunnableAdapter(R(T::*method)(Args...))
-      : method_(method) {
+  template <typename... RunArgs>
+  static R Invoke(R(__fastcall* function)(Args...), RunArgs&&... args) {
+    return function(std::forward<RunArgs>(args)...);
   }
+};
+
+#endif  // defined(OS_WIN) && !defined(ARCH_CPU_X86_64)
+
+// For methods.
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...)> {
+  using RunType = R(Receiver*, Args...);
+  static constexpr bool is_method = true;
+  static constexpr bool is_nullable = true;
 
-  template <typename Receiver, typename... RunArgs>
-  R Run(Receiver&& receiver_ptr, RunArgs&&... args) const {
+  template <typename ReceiverPtr, typename... RunArgs>
+  static R Invoke(R (Receiver::*method)(Args...),
+                  ReceiverPtr&& receiver_ptr,
+                  RunArgs&&... args) {
     // Clang skips CV qualifier check on a method pointer invocation when the
     // receiver is a subclass. Store the receiver into a const reference to
     // T to ensure the CV check works.
     // https://llvm.org/bugs/show_bug.cgi?id=27037
-    T& receiver = *receiver_ptr;
-    return (receiver.*method_)(std::forward<RunArgs>(args)...);
+    Receiver& receiver = *receiver_ptr;
+    return (receiver.*method)(std::forward<RunArgs>(args)...);
   }
-
- private:
-  R (T::*method_)(Args...);
 };
 
-// Const Method.
-template <typename R, typename T, typename... Args>
-class RunnableAdapter<R(T::*)(Args...) const> {
- public:
-  using RunType = R(const T*, Args...);
-  using IsMethod = std::true_type;
-
-  explicit RunnableAdapter(R(T::*method)(Args...) const)
-      : method_(method) {
-  }
-
-  template <typename Receiver, typename... RunArgs>
-  R Run(Receiver&& receiver_ptr, RunArgs&&... args) const {
+// For const methods.
+template <typename R, typename Receiver, typename... Args>
+struct FunctorTraits<R (Receiver::*)(Args...) const> {
+  using RunType = R(const Receiver*, Args...);
+  static constexpr bool is_method = true;
+  static constexpr bool is_nullable = true;
+
+  template <typename ReceiverPtr, typename... RunArgs>
+  static R Invoke(R (Receiver::*method)(Args...) const,
+                  ReceiverPtr&& receiver_ptr,
+                  RunArgs&&... args) {
     // Clang skips CV qualifier check on a method pointer invocation when the
-    // receiver is a subclass. Store the receiver into a unqualified reference
-    // to T to ensure the CV check works.
+    // receiver is a subclass. Store the receiver into a const reference to
+    // T to ensure the CV check works.
     // https://llvm.org/bugs/show_bug.cgi?id=27037
-    const T& receiver = *receiver_ptr;
-    return (receiver.*method_)(std::forward<RunArgs>(args)...);
+    const Receiver& receiver = *receiver_ptr;
+    return (receiver.*method)(std::forward<RunArgs>(args)...);
   }
-
- private:
-  R (T::*method_)(Args...) const;
-};
-
-
-// ForceVoidReturn<>
-//
-// Set of templates that support forcing the function return type to void.
-template <typename Sig>
-struct ForceVoidReturn;
-
-template <typename R, typename... Args>
-struct ForceVoidReturn<R(Args...)> {
-  // MSVC 2013 doesn't support Type Alias of function types.
-  // Revisit this after we update it to newer version.
-  typedef void RunType(Args...);
-};
-
-
-// FunctorTraits<>
-//
-// See description at top of file.
-template <typename T>
-struct FunctorTraits {
-  using RunnableType = RunnableAdapter<T>;
-  using RunType = typename RunnableType::RunType;
 };
 
+// For IgnoreResults.
 template <typename T>
-struct FunctorTraits<IgnoreResultHelper<T>> {
-  using RunnableType = typename FunctorTraits<T>::RunnableType;
+struct FunctorTraits<IgnoreResultHelper<T>> : FunctorTraits<T> {
   using RunType =
-      typename ForceVoidReturn<typename RunnableType::RunType>::RunType;
+      typename ForceVoidReturn<typename FunctorTraits<T>::RunType>::RunType;
+
+  template <typename IgnoreResultType, typename... RunArgs>
+  static void Invoke(IgnoreResultType&& ignore_result_helper,
+                     RunArgs&&... args) {
+    FunctorTraits<T>::Invoke(
+        std::forward<IgnoreResultType>(ignore_result_helper).functor_,
+        std::forward<RunArgs>(args)...);
+  }
 };
 
-template <typename T>
-struct FunctorTraits<Callback<T>> {
-  using RunnableType = Callback<T> ;
-  using RunType = typename Callback<T>::RunType;
+// For Callbacks.
+template <typename R, typename... Args,
+          CopyMode copy_mode, RepeatMode repeat_mode>
+struct FunctorTraits<Callback<R(Args...), copy_mode, repeat_mode>> {
+  using RunType = R(Args...);
+  static constexpr bool is_method = false;
+  static constexpr bool is_nullable = true;
+
+  template <typename CallbackType, typename... RunArgs>
+  static R Invoke(CallbackType&& callback, RunArgs&&... args) {
+    DCHECK(!callback.is_null());
+    return std::forward<CallbackType>(callback).Run(
+        std::forward<RunArgs>(args)...);
+  }
 };
 
-
-// MakeRunnable<>
-//
-// Converts a passed in functor to a RunnableType using type inference.
-
-template <typename T>
-typename FunctorTraits<T>::RunnableType MakeRunnable(const T& t) {
-  return RunnableAdapter<T>(t);
-}
-
-template <typename T>
-typename FunctorTraits<T>::RunnableType
-MakeRunnable(const IgnoreResultHelper<T>& t) {
-  return MakeRunnable(t.functor_);
-}
-
-template <typename T>
-const typename FunctorTraits<Callback<T>>::RunnableType&
-MakeRunnable(const Callback<T>& t) {
-  DCHECK(!t.is_null());
-  return t;
-}
-
-
 // InvokeHelper<>
 //
-// There are 3 logical InvokeHelper<> specializations: normal, void-return,
-// WeakCalls.
+// There are 2 logical InvokeHelper<> specializations: normal, WeakCalls.
 //
 // The normal type just calls the underlying runnable.
 //
-// We need a InvokeHelper to handle void return types in order to support
-// IgnoreResult().  Normally, if the Runnable's RunType had a void return,
-// the template system would just accept "return functor.Run()" ignoring
-// the fact that a void function is being used with return. This piece of
-// sugar breaks though when the Runnable's RunType is not void.  Thus, we
-// need a partial specialization to change the syntax to drop the "return"
-// from the invocation call.
-//
-// WeakCalls similarly need special syntax that is applied to the first
-// argument to check if they should no-op themselves.
+// WeakCalls need special syntax that is applied to the first argument to check
+// if they should no-op themselves.
 template <bool is_weak_call, typename ReturnType>
 struct InvokeHelper;
 
 template <typename ReturnType>
 struct InvokeHelper<false, ReturnType> {
-  template <typename Runnable, typename... RunArgs>
-  static inline ReturnType MakeItSo(Runnable&& runnable, RunArgs&&... args) {
-    return std::forward<Runnable>(runnable).Run(std::forward<RunArgs>(args)...);
+  template <typename Functor, typename... RunArgs>
+  static inline ReturnType MakeItSo(Functor&& functor, RunArgs&&... args) {
+    using Traits = FunctorTraits<typename std::decay<Functor>::type>;
+    return Traits::Invoke(std::forward<Functor>(functor),
+                          std::forward<RunArgs>(args)...);
   }
 };
 
-template <>
-struct InvokeHelper<false, void> {
-  template <typename Runnable, typename... RunArgs>
-  static inline void MakeItSo(Runnable&& runnable, RunArgs&&... args) {
-    std::forward<Runnable>(runnable).Run(std::forward<RunArgs>(args)...);
-  }
-};
-
-template <>
-struct InvokeHelper<true, void> {
-  template <typename Runnable, typename BoundWeakPtr, typename... RunArgs>
-  static void MakeItSo(Runnable&& runnable,
-                       BoundWeakPtr&& weak_ptr,
-                       RunArgs&&... args) {
-    if (!weak_ptr) {
-      return;
-    }
-    std::forward<Runnable>(runnable).Run(
-        std::forward<BoundWeakPtr>(weak_ptr), std::forward<RunArgs>(args)...);
-  }
-};
-
-#if !defined(_MSC_VER)
-
 template <typename ReturnType>
 struct InvokeHelper<true, ReturnType> {
   // WeakCalls are only supported for functions with a void return type.
@@ -320,9 +294,19 @@ struct InvokeHelper<true, ReturnType> {
   // is invalidated.
   static_assert(std::is_void<ReturnType>::value,
                 "weak_ptrs can only bind to methods without return values");
-};
 
-#endif
+  template <typename Functor, typename BoundWeakPtr, typename... RunArgs>
+  static inline void MakeItSo(Functor&& functor,
+                              BoundWeakPtr&& weak_ptr,
+                              RunArgs&&... args) {
+    if (!weak_ptr)
+      return;
+    using Traits = FunctorTraits<typename std::decay<Functor>::type>;
+    Traits::Invoke(std::forward<Functor>(functor),
+                   std::forward<BoundWeakPtr>(weak_ptr),
+                   std::forward<RunArgs>(args)...);
+  }
+};
 
 // Invoker<>
 //
@@ -332,6 +316,19 @@ struct Invoker;
 
 template <typename StorageType, typename R, typename... UnboundArgs>
 struct Invoker<StorageType, R(UnboundArgs...)> {
+  static R RunOnce(BindStateBase* base, UnboundArgs&&... unbound_args) {
+    // Local references to make debugger stepping easier. If in a debugger,
+    // you really want to warp ahead and step through the
+    // InvokeHelper<>::MakeItSo() call below.
+    StorageType* storage = static_cast<StorageType*>(base);
+    static constexpr size_t num_bound_args =
+        std::tuple_size<decltype(storage->bound_args_)>::value;
+    return RunImpl(std::move(storage->functor_),
+                   std::move(storage->bound_args_),
+                   MakeIndexSequence<num_bound_args>(),
+                   std::forward<UnboundArgs>(unbound_args)...);
+  }
+
   static R Run(BindStateBase* base, UnboundArgs&&... unbound_args) {
     // Local references to make debugger stepping easier. If in a debugger,
     // you really want to warp ahead and step through the
@@ -339,19 +336,20 @@ struct Invoker<StorageType, R(UnboundArgs...)> {
     const StorageType* storage = static_cast<StorageType*>(base);
     static constexpr size_t num_bound_args =
         std::tuple_size<decltype(storage->bound_args_)>::value;
-    return RunImpl(storage->runnable_,
+    return RunImpl(storage->functor_,
                    storage->bound_args_,
                    MakeIndexSequence<num_bound_args>(),
                    std::forward<UnboundArgs>(unbound_args)...);
   }
 
-  template <typename Runnable, typename BoundArgsTuple, size_t... indices>
-  static inline R RunImpl(Runnable&& runnable,
+ private:
+  template <typename Functor, typename BoundArgsTuple, size_t... indices>
+  static inline R RunImpl(Functor&& functor,
                           BoundArgsTuple&& bound,
                           IndexSequence<indices...>,
                           UnboundArgs&&... unbound_args) {
     static constexpr bool is_method =
-        HasIsMethodTag<typename std::decay<Runnable>::type>::value;
+        FunctorTraits<typename std::decay<Functor>::type>::is_method;
 
     using DecayedArgsTuple = typename std::decay<BoundArgsTuple>::type;
     static constexpr bool is_weak_call =
@@ -361,74 +359,188 @@ struct Invoker<StorageType, R(UnboundArgs...)> {
                          DecayedArgsTuple>::type...>::value;
 
     return InvokeHelper<is_weak_call, R>::MakeItSo(
-        std::forward<Runnable>(runnable),
-        Unwrap(std::get<indices>(std::forward<BoundArgsTuple>(bound)))...,
+        std::forward<Functor>(functor),
+        Unwrap(base::get<indices>(std::forward<BoundArgsTuple>(bound)))...,
         std::forward<UnboundArgs>(unbound_args)...);
   }
 };
 
-// Used to implement MakeArgsStorage.
-template <bool is_method, typename... BoundArgs>
-struct MakeArgsStorageImpl {
-  using Type = std::tuple<BoundArgs...>;
-};
-
-template <typename Obj, typename... BoundArgs>
-struct MakeArgsStorageImpl<true, Obj*, BoundArgs...> {
-  using Type = std::tuple<scoped_refptr<Obj>, BoundArgs...>;
-};
-
-// Constructs a tuple type to store BoundArgs into BindState.
-// This wraps the first argument into a scoped_refptr if |is_method| is true and
-// the first argument is a raw pointer.
-// Other arguments are adjusted for store and packed into a tuple.
-template <bool is_method, typename... BoundArgs>
-using MakeArgsStorage = typename MakeArgsStorageImpl<
-  is_method, typename std::decay<BoundArgs>::type...>::Type;
-
 // Used to implement MakeUnboundRunType.
 template <typename Functor, typename... BoundArgs>
 struct MakeUnboundRunTypeImpl {
-  using RunType = typename FunctorTraits<Functor>::RunType;
+  using RunType =
+      typename FunctorTraits<typename std::decay<Functor>::type>::RunType;
   using ReturnType = ExtractReturnType<RunType>;
   using Args = ExtractArgs<RunType>;
   using UnboundArgs = DropTypeListItem<sizeof...(BoundArgs), Args>;
   using Type = MakeFunctionType<ReturnType, UnboundArgs>;
 };
+template <typename Functor>
+typename std::enable_if<FunctorTraits<Functor>::is_nullable, bool>::type
+IsNull(const Functor& functor) {
+  return !functor;
+}
+
+template <typename Functor>
+typename std::enable_if<!FunctorTraits<Functor>::is_nullable, bool>::type
+IsNull(const Functor&) {
+  return false;
+}
+
+template <typename Functor, typename... BoundArgs>
+struct BindState;
+
+template <typename BindStateType, typename SFINAE = void>
+struct CancellationChecker {
+  static constexpr bool is_cancellable = false;
+  static bool Run(const BindStateBase*) {
+    return false;
+  }
+};
+
+template <typename Functor, typename... BoundArgs>
+struct CancellationChecker<
+    BindState<Functor, BoundArgs...>,
+    typename std::enable_if<IsWeakMethod<FunctorTraits<Functor>::is_method,
+                                         BoundArgs...>::value>::type> {
+  static constexpr bool is_cancellable = true;
+  static bool Run(const BindStateBase* base) {
+    using BindStateType = BindState<Functor, BoundArgs...>;
+    const BindStateType* bind_state = static_cast<const BindStateType*>(base);
+    return !base::get<0>(bind_state->bound_args_);
+  }
+};
+
+template <typename Signature, typename... BoundArgs>
+struct CancellationChecker<BindState<Callback<Signature>, BoundArgs...>> {
+  static constexpr bool is_cancellable = true;
+  static bool Run(const BindStateBase* base) {
+    using Functor = Callback<Signature>;
+    using BindStateType = BindState<Functor, BoundArgs...>;
+    const BindStateType* bind_state = static_cast<const BindStateType*>(base);
+    return bind_state->functor_.IsCancelled();
+  }
+};
+
+// Template helpers to detect using Bind() on a base::Callback without any
+// additional arguments. In that case, the original base::Callback object should
+// just be directly used.
+template <typename Functor, typename... BoundArgs>
+struct BindingCallbackWithNoArgs {
+  static constexpr bool value = false;
+};
+
+template <typename Signature,
+          typename... BoundArgs,
+          CopyMode copy_mode,
+          RepeatMode repeat_mode>
+struct BindingCallbackWithNoArgs<Callback<Signature, copy_mode, repeat_mode>,
+                                 BoundArgs...> {
+  static constexpr bool value = sizeof...(BoundArgs) == 0;
+};
 
 // BindState<>
 //
-// This stores all the state passed into Bind() and is also where most
-// of the template resolution magic occurs.
-//
-// Runnable is the functor we are binding arguments to.
-//
-// BoundArgs contains the storage type for all the bound arguments.
-template <typename Runnable, typename... BoundArgs>
-struct BindState final : public BindStateBase {
- private:
-  using RunnableType = typename std::decay<Runnable>::type;
+// This stores all the state passed into Bind().
+template <typename Functor, typename... BoundArgs>
+struct BindState final : BindStateBase {
+  using IsCancellable = std::integral_constant<
+      bool, CancellationChecker<BindState>::is_cancellable>;
+
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  explicit BindState(BindStateBase::InvokeFuncStorage invoke_func,
+                     ForwardFunctor&& functor,
+                     ForwardBoundArgs&&... bound_args)
+      // IsCancellable is std::false_type if the CancellationChecker<>::Run
+      // returns always false. Otherwise, it's std::true_type.
+      : BindState(IsCancellable{},
+                  invoke_func,
+                  std::forward<ForwardFunctor>(functor),
+                  std::forward<ForwardBoundArgs>(bound_args)...) {
+    static_assert(!BindingCallbackWithNoArgs<Functor, BoundArgs...>::value,
+                  "Attempting to bind a base::Callback with no additional "
+                  "arguments: save a heap allocation and use the original "
+                  "base::Callback object");
+  }
 
-  static constexpr bool is_method = HasIsMethodTag<RunnableType>::value;
+  Functor functor_;
+  std::tuple<BoundArgs...> bound_args_;
 
- public:
-  template <typename... ForwardArgs>
-  explicit BindState(RunnableType runnable, ForwardArgs&&... bound_args)
-      : BindStateBase(&Destroy),
-        runnable_(std::move(runnable)),
-        bound_args_(std::forward<ForwardArgs>(bound_args)...) {}
+ private:
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  explicit BindState(std::true_type,
+                     BindStateBase::InvokeFuncStorage invoke_func,
+                     ForwardFunctor&& functor,
+                     ForwardBoundArgs&&... bound_args)
+      : BindStateBase(invoke_func, &Destroy,
+                      &CancellationChecker<BindState>::Run),
+        functor_(std::forward<ForwardFunctor>(functor)),
+        bound_args_(std::forward<ForwardBoundArgs>(bound_args)...) {
+    DCHECK(!IsNull(functor_));
+  }
 
-  RunnableType runnable_;
-  MakeArgsStorage<is_method, BoundArgs...> bound_args_;
+  template <typename ForwardFunctor, typename... ForwardBoundArgs>
+  explicit BindState(std::false_type,
+                     BindStateBase::InvokeFuncStorage invoke_func,
+                     ForwardFunctor&& functor,
+                     ForwardBoundArgs&&... bound_args)
+      : BindStateBase(invoke_func, &Destroy),
+        functor_(std::forward<ForwardFunctor>(functor)),
+        bound_args_(std::forward<ForwardBoundArgs>(bound_args)...) {
+    DCHECK(!IsNull(functor_));
+  }
 
- private:
   ~BindState() {}
 
-  static void Destroy(BindStateBase* self) {
-    delete static_cast<BindState*>(self);
+  static void Destroy(const BindStateBase* self) {
+    delete static_cast<const BindState*>(self);
   }
 };
 
+// Used to implement MakeBindStateType.
+template <bool is_method, typename Functor, typename... BoundArgs>
+struct MakeBindStateTypeImpl;
+
+template <typename Functor, typename... BoundArgs>
+struct MakeBindStateTypeImpl<false, Functor, BoundArgs...> {
+  static_assert(!HasRefCountedTypeAsRawPtr<BoundArgs...>::value,
+                "A parameter is a refcounted type and needs scoped_refptr.");
+  using Type = BindState<typename std::decay<Functor>::type,
+                         typename std::decay<BoundArgs>::type...>;
+};
+
+template <typename Functor>
+struct MakeBindStateTypeImpl<true, Functor> {
+  using Type = BindState<typename std::decay<Functor>::type>;
+};
+
+template <typename Functor, typename Receiver, typename... BoundArgs>
+struct MakeBindStateTypeImpl<true, Functor, Receiver, BoundArgs...> {
+  static_assert(
+      !std::is_array<typename std::remove_reference<Receiver>::type>::value,
+      "First bound argument to a method cannot be an array.");
+  static_assert(!HasRefCountedTypeAsRawPtr<BoundArgs...>::value,
+                "A parameter is a refcounted type and needs scoped_refptr.");
+
+ private:
+  using DecayedReceiver = typename std::decay<Receiver>::type;
+
+ public:
+  using Type = BindState<
+      typename std::decay<Functor>::type,
+      typename std::conditional<
+          std::is_pointer<DecayedReceiver>::value,
+          scoped_refptr<typename std::remove_pointer<DecayedReceiver>::type>,
+          DecayedReceiver>::type,
+      typename std::decay<BoundArgs>::type...>;
+};
+
+template <typename Functor, typename... BoundArgs>
+using MakeBindStateType = typename MakeBindStateTypeImpl<
+    FunctorTraits<typename std::decay<Functor>::type>::is_method,
+    Functor,
+    BoundArgs...>::Type;
+
 }  // namespace internal
 
 // Returns a RunType of bound functor.