Plugin Power Saver: Add missing RenderFrame null-checks in placeholders

components/plugins/renderer/loadable_plugin_placeholder.cc

 // Copyright 2015 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 "components/plugins/renderer/loadable_plugin_placeholder.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 23 matching lines @@
 using content::PluginInstanceThrottler;
 using content::RenderFrame;
 using content::RenderThread;
 
 namespace plugins {
 
 void LoadablePluginPlaceholder::BlockForPowerSaverPoster() {
   DCHECK(!is_blocked_for_power_saver_poster_);
   is_blocked_for_power_saver_poster_ = true;
 
+  DCHECK(render_frame());
   render_frame()->RegisterPeripheralPlugin(
       url::Origin(GURL(GetPluginParams().url)),
       base::Bind(&LoadablePluginPlaceholder::MarkPluginEssential,
                  weak_factory_.GetWeakPtr(),
                  PluginInstanceThrottler::UNTHROTTLE_METHOD_BY_WHITELIST));
 }
 
 void LoadablePluginPlaceholder::SetPremadePlugin(
     content::PluginInstanceThrottler* throttler) {
   DCHECK(throttler);
@@ skipping 120 matching lines @@
   // Pass through JavaScript access to the underlying throttled plugin.
   if (premade_throttler_ && premade_throttler_->GetWebPlugin()) {
     return premade_throttler_->GetWebPlugin()->V8ScriptableObject(isolate);
   }
   return v8::Local<v8::Object>();
 }
 
 void LoadablePluginPlaceholder::OnUnobscuredRectUpdate(
     const gfx::Rect& unobscured_rect) {
   DCHECK(content::RenderThread::Get());
+  if (!render_frame())
+    return;
 
   if (!plugin() || !finished_loading_)
     return;
 
   if (!is_blocked_for_tinyness_ && !is_blocked_for_power_saver_poster_)
     return;
 
   if (unobscured_rect_ == unobscured_rect)
     return;
 
@@ skipping 174 matching lines @@
   return identifier_;
 }
 
 bool LoadablePluginPlaceholder::LoadingBlocked() const {
   DCHECK(allow_loading_);
   return is_blocked_for_tinyness_ || is_blocked_for_background_tab_ ||
          is_blocked_for_power_saver_poster_ || is_blocked_for_prerendering_;
 }
 
 }  // namespace plugins