exhibit 1: explicit null checks

chrome/browser/ui/views/tabs/browser_tab_strip_controller.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/ui/views/tabs/browser_tab_strip_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ skipping 494 matching lines @@
 }
 
 void BrowserTabStripController::SetTabRendererDataFromModel(
     WebContents* contents,
     int model_index,
     TabRendererData* data,
     TabStatus tab_status) {
   TabContents* tab_contents = TabContents::FromWebContents(contents);
 
   // TODO: Convert data->favicon to gfx::Image.
-  data->favicon =
-      tab_contents->favicon_tab_helper()->GetFavicon().AsBitmap();
+  const gfx::Image& icon = tab_contents->favicon_tab_helper()->GetFavicon();
+  data->favicon = icon.IsEmpty() ? SkBitmap() : *icon.ToSkBitmap();
   data->network_state = TabContentsNetworkState(contents);
   data->title = contents->GetTitle();
   data->url = contents->GetURL();
   data->loading = contents->IsLoading();
   data->crashed_status = contents->GetCrashedStatus();
   data->incognito = contents->GetBrowserContext()->IsOffTheRecord();
   data->show_icon = tab_contents->favicon_tab_helper()->ShouldDisplayFavicon();
   data->mini = model_->IsMiniTab(model_index);
   data->blocked = model_->IsTabBlocked(model_index);
   data->app = tab_contents->extension_tab_helper()->is_app();
@@ skipping 49 matching lines @@
   SetTabRendererDataFromModel(contents->web_contents(), index, &data, NEW_TAB);
   tabstrip_->AddTabAt(index, data, is_active);
 }
 
 void BrowserTabStripController::UpdateLayoutType() {
   bool adjust_layout = false;
   TabStripLayoutType layout_type =
       DetermineTabStripLayout(g_browser_process->local_state(), &adjust_layout);
   tabstrip_->SetLayoutType(layout_type, adjust_layout);
 }