aw: Fix hardware init/tear down in pop up flow

android_webview/browser/gl_view_renderer_manager.cc

 // Copyright 2013 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 "android_webview/browser/gl_view_renderer_manager.h"
 
 #include "base/logging.h"
 #include "base/threading/platform_thread.h"
 
 namespace android_webview {
 
 using base::AutoLock;
 
 namespace {
 base::LazyInstance<GLViewRendererManager>::Leaky g_view_renderer_manager =
     LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
 // static
 GLViewRendererManager* GLViewRendererManager::GetInstance() {
   return g_view_renderer_manager.Pointer();
 }
 
 GLViewRendererManager::GLViewRendererManager() {}
 
 GLViewRendererManager::~GLViewRendererManager() {}
 
+GLViewRendererManager::Key GLViewRendererManager::NullKey() {
+  AutoLock auto_lock(lock_);
+  return mru_list_.end();
+}
+
 GLViewRendererManager::Key GLViewRendererManager::PushBack(RendererType view) {
   AutoLock auto_lock(lock_);
   DCHECK(mru_list_.end() ==
          std::find(mru_list_.begin(), mru_list_.end(), view));
   mru_list_.push_back(view);
   Key back = mru_list_.end();
   back--;
   return back;
 }
 
@@ skipping 11 matching lines @@
 
 GLViewRendererManager::RendererType
 GLViewRendererManager::GetMostRecentlyDrawn() const {
   AutoLock auto_lock(lock_);
   if (mru_list_.begin() == mru_list_.end())
     return NULL;
   return *mru_list_.begin();
 }
 
 }  // namespace android_webview