1 files changed, 66 insertions, 2 deletions
diff --git a/chromium/cc/resources/shared_bitmap.cc b/chromium/cc/resources/shared_bitmap.cc
index 3a6fc3589e3..31cf245151c 100644
--- a/chromium/cc/resources/shared_bitmap.cc
+++ b/chromium/cc/resources/shared_bitmap.cc
@@ -4,14 +4,78 @@
 
 #include "cc/resources/shared_bitmap.h"
 
+#include "base/logging.h"
+#include "base/numerics/safe_math.h"
+#include "base/rand_util.h"
+
 namespace cc {
 
 SharedBitmap::SharedBitmap(
     base::SharedMemory* memory,
     const SharedBitmapId& id,
-    const base::Callback<void(SharedBitmap*)>& free_callback)
-    : memory_(memory), id_(id), free_callback_(free_callback) {}
+    const base::Callback<void(SharedBitmap* bitmap)>& free_callback)
+    : memory_(memory),
+      pixels_(static_cast<uint8*>(memory_->memory())),
+      id_(id),
+      free_callback_(free_callback) {
+}
+
+SharedBitmap::SharedBitmap(
+    uint8* pixels,
+    const SharedBitmapId& id,
+    const base::Callback<void(SharedBitmap* bitmap)>& free_callback)
+    : memory_(NULL), pixels_(pixels), id_(id), free_callback_(free_callback) {
+}
 
 SharedBitmap::~SharedBitmap() { free_callback_.Run(this); }
 
+// static
+bool SharedBitmap::SizeInBytes(const gfx::Size& size, size_t* size_in_bytes) {
+  if (size.IsEmpty())
+    return false;
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  if (!s.IsValid())
+    return false;
+  *size_in_bytes = s.ValueOrDie();
+  return true;
+}
+
+// static
+size_t SharedBitmap::CheckedSizeInBytes(const gfx::Size& size) {
+  CHECK(!size.IsEmpty());
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s.ValueOrDie();
+}
+
+// static
+size_t SharedBitmap::UncheckedSizeInBytes(const gfx::Size& size) {
+  DCHECK(VerifySizeInBytes(size));
+  size_t s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s;
+}
+
+// static
+bool SharedBitmap::VerifySizeInBytes(const gfx::Size& size) {
+  if (size.IsEmpty())
+    return false;
+  base::CheckedNumeric<size_t> s = 4;
+  s *= size.width();
+  s *= size.height();
+  return s.IsValid();
+}
+
+// static
+SharedBitmapId SharedBitmap::GenerateId() {
+  SharedBitmapId id;
+  // Needs cryptographically-secure random numbers.
+  base::RandBytes(id.name, sizeof(id.name));
+  return id;
+}
+
 }  // namespace cc