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

chrome/renderer/chrome_content_renderer_client.h

Index: chrome/renderer/chrome_content_renderer_client.h
diff --git a/chrome/renderer/chrome_content_renderer_client.h b/chrome/renderer/chrome_content_renderer_client.h
index ad629bd7abeee5c0bcd6e2bc7b33dd97373138fc..ec3ba90d9dbc1c4cdf5c10c8b3730714bbf67576 100644
--- a/chrome/renderer/chrome_content_renderer_client.h
+++ b/chrome/renderer/chrome_content_renderer_client.h
@@ -8,6 +8,8 @@
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
 #include "content/renderer/content_renderer_client.h"
 
 class ChromeRenderProcessObserver;
@@ -15,6 +17,7 @@ class ExtensionDispatcher;
 class RendererHistogramSnapshots;
 class RendererNetPredictor;
 class SpellCheck;
+class SpellCheckProvider;
 class VisitedLinkSlave;
 
 namespace safe_browsing {
@@ -29,7 +32,8 @@ class PluginGroup;
 
 namespace chrome {
 
-class ChromeContentRendererClient : public content::ContentRendererClient {
+class ChromeContentRendererClient : public content::ContentRendererClient,
+                                    public NotificationObserver {
  public:
   ChromeContentRendererClient();
   virtual ~ChromeContentRendererClient();
@@ -73,6 +77,15 @@ class ChromeContentRendererClient : public content::ContentRendererClient {
   // For testing.
   void SetExtensionDispatcher(ExtensionDispatcher* extension_dispatcher);
 
+  // NotificationObserver
+  void Observe(int type,
+               const NotificationSource& source,
+               const NotificationDetails& details) OVERRIDE;
+
+  // Called in low-memory conditions to dump the memory used by the spellchecker
+  // and start over.
+  void ResetSpellCheck();
+
  private:
   WebKit::WebPlugin* CreatePluginPlaceholder(
       RenderView* render_view,
@@ -93,8 +106,11 @@ class ChromeContentRendererClient : public content::ContentRendererClient {
   scoped_ptr<RendererHistogramSnapshots> histogram_snapshots_;
   scoped_ptr<RendererNetPredictor> net_predictor_;
   scoped_ptr<SpellCheck> spellcheck_;
+  scoped_ptr<SpellCheckProvider> spellcheck_provider_;
   scoped_ptr<VisitedLinkSlave> visited_link_slave_;
   scoped_ptr<safe_browsing::PhishingClassifierFilter> phishing_classifier_;
+
+  NotificationRegistrar registrar_;
 };
 
 }  // namespace chrome