Fix RenderWidgetHostViewGuest leak.

content/browser/frame_host/render_widget_host_view_guest.cc

 // Copyright 2014 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 "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "content/browser/browser_plugin/browser_plugin_guest.h"
 #include "content/browser/frame_host/render_widget_host_view_guest.h"
@@ skipping 28 matching lines @@
   gesture_event.sourceDevice = blink::WebGestureDeviceTouchscreen;
   return gesture_event;
 }
 #endif  // defined(USE_AURA)
 
 }  // namespace
 
 RenderWidgetHostViewGuest::RenderWidgetHostViewGuest(
     RenderWidgetHost* widget_host,
     BrowserPluginGuest* guest,
-    RenderWidgetHostViewBase* platform_view)
+    base::WeakPtr<RenderWidgetHostViewBase> platform_view)
     : RenderWidgetHostViewChildFrame(widget_host),
       // |guest| is NULL during test.
       guest_(guest ? guest->AsWeakPtr() : base::WeakPtr<BrowserPluginGuest>()),
       platform_view_(platform_view) {
 #if defined(USE_AURA)
   gesture_recognizer_.reset(ui::GestureRecognizer::Create());
   gesture_recognizer_->AddGestureEventHelper(this);
 #endif  // defined(USE_AURA)
 }
 
@@ skipping 110 matching lines @@
   platform_view_->RenderProcessGone(status, error_code);
   // Destroy the guest view instance only, so we don't end up calling
   // platform_view_->Destroy().
   DestroyGuestView();
 }
 
 void RenderWidgetHostViewGuest::Destroy() {
   // The RenderWidgetHost's destruction led here, so don't call it.
   DestroyGuestView();
 
-  platform_view_->Destroy();
+  if (platform_view_)  // The platform view might have been destroyed already.
+    platform_view_->Destroy();
 }
 
 gfx::Size RenderWidgetHostViewGuest::GetPhysicalBackingSize() const {
   return RenderWidgetHostViewBase::GetPhysicalBackingSize();
 }
 
 base::string16 RenderWidgetHostViewGuest::GetSelectedText() const {
   return platform_view_->GetSelectedText();
 }
 
@@ skipping 219 matching lines @@
   gfx::Rect embedder_bounds;
   if (rwhv)
     embedder_bounds = rwhv->GetViewBounds();
 
   gfx::Vector2d guest_offset = gfx::Vector2d(
       // Horizontal offset of guest from embedder.
       guest_bounds.x() - embedder_bounds.x(),
       // Vertical offset from guest's top to embedder's bottom edge.
       embedder_bounds.bottom() - guest_bounds.y());
 
-  RenderWidgetHostViewMacDictionaryHelper helper(platform_view_);
+  RenderWidgetHostViewMacDictionaryHelper helper(platform_view_.get());
   helper.SetTargetView(rwhv);
   helper.set_offset(guest_offset);
   helper.ShowDefinitionForSelection();
 }
 
 bool RenderWidgetHostViewGuest::SupportsSpeech() const {
   return platform_view_->SupportsSpeech();
 }
 
 void RenderWidgetHostViewGuest::SpeakSelection() {
@@ skipping 162 matching lines @@
   }
 
   if (blink::WebInputEvent::isGestureEventType(event->type)) {
     host_->ForwardGestureEvent(
         *static_cast<const blink::WebGestureEvent*>(event));
     return;
   }
 }
 
 }  // namespace content