Add mojo::StrongBindingSet and use it in GeolocationServiceContext.

content/browser/frame_host/render_frame_host_delegate.h

Index: content/browser/frame_host/render_frame_host_delegate.h
diff --git a/content/browser/frame_host/render_frame_host_delegate.h b/content/browser/frame_host/render_frame_host_delegate.h
index 13f78d9c936f2208f03007c4ec71f5e9e3b291df..df063d558f177533df0c384aa2081e8cc6422e53 100644
--- a/content/browser/frame_host/render_frame_host_delegate.h
+++ b/content/browser/frame_host/render_frame_host_delegate.h
@@ -27,7 +27,6 @@ class Message;
 }
 
 namespace content {
-class GeolocationServiceContext;
 class PageState;
 class RenderFrameHost;
 class WakeLockServiceContext;
@@ -139,9 +138,6 @@ class CONTENT_EXPORT RenderFrameHostDelegate {
       RenderFrameHost* render_frame_host,
       int browser_plugin_instance_id);
 
-  // Gets the GeolocationServiceContext associated with this delegate.
-  virtual GeolocationServiceContext* GetGeolocationServiceContext();
-
   // Gets the WakeLockServiceContext associated with this delegate.
   virtual WakeLockServiceContext* GetWakeLockServiceContext();