Fix single-process mode

Destroy RenderprocesHostimpl first then the WebEngineContext.
RenderProcessHostImpl's destructor may use the default BrowserContext
stored by the WebEngineContext.

Task-number: QTBUG-45722
Change-Id: Ide8875a89bd339ecf65ddd32a5f00842102c1c43
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@theqtcompany.com>

3 files changed, 25 insertions, 1 deletions

diff --git a/src/core/content_browser_client_qt.cpp b/src/core/content_browser_client_qt.cpp
index 3d318047b..fdfbaf0f5 100644
--- a/src/core/content_browser_client_qt.cpp
+++ b/src/core/content_browser_client_qt.cpp
@@ -71,6 +71,7 @@
 #include "resource_dispatcher_host_delegate_qt.h"
 #include "user_script_controller_host.h"
 #include "web_contents_delegate_qt.h"
+#include "web_engine_context.h"
 #include "web_engine_library_info.h"
 
 #include <QGuiApplication>
@@ -218,6 +219,9 @@ public:
 
     void PostMainMessageLoopRun()
     {
+        // The BrowserContext's destructor uses the MessageLoop so it should be deleted
+        // right before the RenderProcessHostImpl's destructor destroys it.
+        WebEngineContext::current()->destroyBrowserContext();
     }
 
     int PreCreateThreads() Q_DECL_OVERRIDE
diff --git a/src/core/web_engine_context.cpp b/src/core/web_engine_context.cpp
index 10d6bdd74..8bc047321 100644
--- a/src/core/web_engine_context.cpp
+++ b/src/core/web_engine_context.cpp
@@ -91,6 +91,10 @@ scoped_refptr<WebEngineContext> sContext;
 
 void destroyContext()
 {
+    // Destroy WebEngineContext before its static pointer is zeroed and destructor called.
+    // Before destroying MessageLoop via destroying BrowserMainRunner destructor
+    // WebEngineContext's pointer is used.
+    sContext->destroy();
     sContext = 0;
 }
 
@@ -136,9 +140,13 @@ bool usingQtQuick2DRenderer()
 
 } // namespace
 
-WebEngineContext::~WebEngineContext()
+void WebEngineContext::destroyBrowserContext()
 {
     m_defaultBrowserContext = 0;
+}
+
+void WebEngineContext::destroy()
+{
     delete m_globalQObject;
     m_globalQObject = 0;
     base::MessagePump::Delegate *delegate = m_runLoop->loop_;
@@ -146,6 +154,15 @@ WebEngineContext::~WebEngineContext()
     while (delegate->DoWork()) { }
     GLContextHelper::destroy();
     m_runLoop->AfterRun();
+
+    // Force to destroy RenderProcessHostImpl by destroying BrowserMainRunner.
+    // RenderProcessHostImpl should be destroyed before WebEngineContext since
+    // default BrowserContext might be used by the RenderprocessHostImpl's destructor.
+    m_browserRunner.reset(0);
+}
+
+WebEngineContext::~WebEngineContext()
+{
 }
 
 scoped_refptr<WebEngineContext> WebEngineContext::current()
diff --git a/src/core/web_engine_context.h b/src/core/web_engine_context.h
index f900c93d8..dea54ef8a 100644
--- a/src/core/web_engine_context.h
+++ b/src/core/web_engine_context.h
@@ -70,6 +70,9 @@ public:
     QtWebEngineCore::BrowserContextAdapter *defaultBrowserContext();
     QObject *globalQObject();
 
+    void destroyBrowserContext();
+    void destroy();
+
 private:
     friend class base::RefCounted<WebEngineContext>;
     WebEngineContext();