Speech Recognition API: Safeguarding against page closes during startup

chrome/browser/speech/speech_recognition_bubble.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 "chrome/browser/speech/speech_recognition_bubble.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop.h"
+#include "chrome/browser/tab_contents/tab_util.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/screen.h"
@@ skipping 95 matching lines @@
 
 base::LazyInstance<SpeechRecognitionBubbleImages> g_images =
     LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 SpeechRecognitionBubble::FactoryMethod SpeechRecognitionBubble::factory_ = NULL;
 const int SpeechRecognitionBubble::kBubbleTargetOffsetX = 10;
 
 SpeechRecognitionBubble* SpeechRecognitionBubble::Create(
-    WebContents* web_contents, Delegate* delegate,
+    int render_process_id, int render_view_id, Delegate* delegate,
     const gfx::Rect& element_rect) {
-  if (factory_)
-    return (*factory_)(web_contents, delegate, element_rect);
+
+  WebContents* web_contents =
+      tab_util::GetWebContentsByID(render_process_id, render_view_id);
 
   // Has the tab already closed before bubble create request was processed?
   if (!web_contents)
     return NULL;
 
-  return CreateNativeBubble(web_contents, delegate, element_rect);
+  if (factory_)
+    return (*factory_)(web_contents, delegate, element_rect);
+
+  return CreateNativeBubble(render_process_id, render_view_id,
+      delegate, element_rect);
 }
 
 SpeechRecognitionBubbleBase::SpeechRecognitionBubbleBase(
-    WebContents* web_contents)
+    int render_process_id, int render_view_id)
     : weak_factory_(this),
       animation_step_(0),
       display_mode_(DISPLAY_MODE_RECORDING),
-      web_contents_(web_contents),
+      render_process_id_(render_process_id),
+      render_view_id_(render_view_id),
       scale_(1.0f) {
+  WebContents* web_contents = GetWebContents();
+  DCHECK(web_contents);

[tommi (sloooow) - chröme, 2014/02/10 22:32:53]

nit: since you check web_contents immediately after, this DCHECK isn't
necessary.
DCHECKs in Chrome state assumptions that are otherwise not checked which may be
slightly different from blink.

   gfx::NativeView view =
-      web_contents_ ? web_contents_->GetView()->GetNativeView() : NULL;
+      web_contents ? web_contents->GetView()->GetNativeView() : NULL;
   gfx::Screen* screen = gfx::Screen::GetScreenFor(view);
   gfx::Display display = screen->GetDisplayNearestWindow(view);
   scale_ = display.device_scale_factor();
 
   const gfx::ImageSkiaRep& rep =
       g_images.Get().mic_empty()->GetRepresentation(scale_);
   mic_image_.reset(new SkBitmap());
   mic_image_->setConfig(SkBitmap::kARGB_8888_Config,
       rep.pixel_width(), rep.pixel_height());
   mic_image_->allocPixels();
@@ skipping 100 matching lines @@
       g_images.Get().mic_empty()->GetRepresentation(scale_).sk_bitmap(),
       0, 0);
   DrawVolumeOverlay(&canvas, *g_images.Get().mic_full(), volume);
   DrawVolumeOverlay(&canvas, *g_images.Get().mic_noise(), noise_volume);
 
   gfx::ImageSkia image(gfx::ImageSkiaRep(*mic_image_.get(), scale_));
   SetImage(image);
 }
 
 WebContents* SpeechRecognitionBubbleBase::GetWebContents() {
-  return web_contents_;
+  return tab_util::GetWebContentsByID(render_process_id_, render_view_id_);
 }
 
 void SpeechRecognitionBubbleBase::SetImage(const gfx::ImageSkia& image) {
   icon_image_ = image;
   UpdateImage();
 }
 
 gfx::ImageSkia SpeechRecognitionBubbleBase::icon_image() {
   return icon_image_;
 }