Forward handling of low-mem message to the content renderer client. Add APIs to handle this case.

chrome/renderer/chrome_content_renderer_client.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_
 #define CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/renderer/content_renderer_client.h"
 
 class ChromeRenderProcessObserver;
 class ExtensionDispatcher;
 class RendererHistogramSnapshots;
 class RendererNetPredictor;
 class SpellCheck;
+class SpellCheckProvider;
 class VisitedLinkSlave;
 
 namespace safe_browsing {
 class PhishingClassifierFilter;
 }
 
 namespace webkit {
 namespace npapi {
 class PluginGroup;
 }
@@ skipping 38 matching lines @@
                                              size_t length) OVERRIDE;
   virtual bool IsLinkVisited(unsigned long long link_hash) OVERRIDE;
   virtual void PrefetchHostName(const char* hostname, size_t length) OVERRIDE;
   virtual bool ShouldOverridePageVisibilityState(
       const RenderView* render_view,
       WebKit::WebPageVisibilityState* override_state) const OVERRIDE;
 
   // For testing.
   void SetExtensionDispatcher(ExtensionDispatcher* extension_dispatcher);
 
+  // Called in low-memory conditions to dump the memory used by the spellchecker
+  // and start over.
+  void OnPurgeMemory();
+
  private:
   WebKit::WebPlugin* CreatePluginImpl(
       RenderView* render_view,
       WebKit::WebFrame* frame,
       const WebKit::WebPluginParams& params,
       bool* is_default_plugin);
 
   WebKit::WebPlugin* CreatePluginPlaceholder(
       RenderView* render_view,
       WebKit::WebFrame* frame,
       const WebKit::WebPluginParams& params,
       const webkit::npapi::PluginGroup& group,
       int resource_id,
       int message_id,
       bool is_blocked_for_prerendering,
       bool allow_loading);
 
   // Returns true if the frame is navigating to an URL either into or out of an
   // extension app's extent.
   bool CrossesExtensionExtents(WebKit::WebFrame* frame, const GURL& new_url);
 
   scoped_ptr<ChromeRenderProcessObserver> chrome_observer_;
   scoped_ptr<ExtensionDispatcher> extension_dispatcher_;
   scoped_ptr<RendererHistogramSnapshots> histogram_snapshots_;
   scoped_ptr<RendererNetPredictor> net_predictor_;
   scoped_ptr<SpellCheck> spellcheck_;
+  // The SpellCheckProvider is a RenderViewObserver, and handles its own
+  // destruction.
+  SpellCheckProvider* spellcheck_provider_;
   scoped_ptr<VisitedLinkSlave> visited_link_slave_;
   scoped_ptr<safe_browsing::PhishingClassifierFilter> phishing_classifier_;
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_RENDERER_CHROME_CONTENT_RENDERER_CLIENT_H_