DO NOT REVIEW Plumb push messaging registration through to gcm.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 38a3c6fb4ddf3225d8772bc7663b70cd27ab7ac7..d7a2e502de6ccca883ce9956bfd20e9b4d3f15fe 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -84,6 +84,7 @@ class BrowserPpapiHost;
 class BrowserURLHandler;
 class LocationProvider;
 class MediaObserver;
+class PushMessagingService;
 class QuotaPermissionContext;
 class RenderProcessHost;
 class RenderViewHost;
@@ -495,6 +496,11 @@ class CONTENT_EXPORT ContentBrowserClient {
   virtual SpeechRecognitionManagerDelegate*
       GetSpeechRecognitionManagerDelegate();
 
+  // Allows the embedder to provide an implementation of PushMessagingService.
+  // Ownership is transferred to the caller. It's valid to return NULL.
+  virtual PushMessagingService* CreatePushMessagingService(
+      BrowserContext* browser_context);
+
   // Getters for common objects.
   virtual net::NetLog* GetNetLog();