Fix the issue that any tab/window closing hotkey will crash the Pepper Flash Fullscreen.

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 167 matching lines @@
 RenderWidgetHostImpl::~RenderWidgetHostImpl() {
   SetView(NULL);
 
   // Clear our current or cached backing store if either remains.
   BackingStoreManager::RemoveBackingStore(this);
 
   GpuSurfaceTracker::Get()->RemoveSurface(surface_id_);
   surface_id_ = 0;
 
   process_->Release(routing_id_);
+
+  if (delegate_)
+    delegate_->RenderWidgetDeleted(this);
 }
 
 // static
 RenderWidgetHostImpl* RenderWidgetHostImpl::From(RenderWidgetHost* rwh) {
   return rwh->AsRenderWidgetHostImpl();
 }
 
 void RenderWidgetHostImpl::SetView(RenderWidgetHostView* view) {
   view_ = RenderWidgetHostViewPort::FromRWHV(view);
 
@@ skipping 758 matching lines @@
       // RawKeyDown event may generate multiple Char events, so we can't reset
       // |suppress_next_char_events_| until we get a KeyUp or a RawKeyDown.
       if (key_event.type == WebKeyboardEvent::Char)
         return;
       // We get a KeyUp or a RawKeyDown event.
       suppress_next_char_events_ = false;
     }
 
     bool is_keyboard_shortcut = false;
     // Only pre-handle the key event if it's not handled by the input method.
-    // A delegate_ of NULL seems impossible but crash reports show that it
-    // can happen (see http://crbug.com/134465). This doesn't seem to happen
-    // with Chrome 22 and later, so checking the delegate_ here can be removed
-    // once Chrome 22 goes to stable..
     if (delegate_ && !key_event.skip_in_browser) {
       // We need to set |suppress_next_char_events_| to true if
       // PreHandleKeyboardEvent() returns true, but |this| may already be
       // destroyed at that time. So set |suppress_next_char_events_| true here,
       // then revert it afterwards when necessary.
       if (key_event.type == WebKeyboardEvent::RawKeyDown)
         suppress_next_char_events_ = true;
 
       // Tab switching/closing accelerators aren't sent to the renderer to avoid
       // a hung/malicious renderer from interfering.
@@ skipping 859 matching lines @@
     key_queue_.pop_front();
 
 #if defined(OS_MACOSX)
     if (!is_hidden_ && view_->PostProcessEventForPluginIme(front_item))
       return;
 #endif
 
     // We only send unprocessed key event upwards if we are not hidden,
     // because the user has moved away from us and no longer expect any effect
     // of this key event.
-    if (!processed && !is_hidden_ && !front_item.skip_in_browser) {
+    if (delegate_ && !processed && !is_hidden_ && !front_item.skip_in_browser) {
       delegate_->HandleKeyboardEvent(front_item);
 
       // WARNING: This RenderWidgetHostImpl can be deallocated at this point
       // (i.e.  in the case of Ctrl+W, where the call to
       // HandleKeyboardEvent destroys this RenderWidgetHostImpl).
     }
   }
 }
 
 void RenderWidgetHostImpl::ActivateDeferredPluginHandles() {
@@ skipping 190 matching lines @@
   // Clear the new_auto_size_ since the empty value is used as a flag to
   // indicate that no callback is in progress (i.e. without this line
   // DelayedAutoResized will not get called again).
   new_auto_size_.SetSize(0, 0);
   if (!should_auto_resize_)
     return;
 
   OnRenderAutoResized(new_size);
 }
 
+void RenderWidgetHostImpl::DetachDelegate() {
+  delegate_ = NULL;
+}
+
 }  // namespace content