Introduce RenderProcessHostObserver, use it in its first client.

content/public/test/mock_render_process_host.cc

 // Copyright (c) 2012 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 "content/public/test/mock_render_process_host.h"
 
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop.h"
 #include "base/time/time.h"
 #include "content/browser/child_process_security_policy_impl.h"
@@ skipping 49 matching lines @@
     IPC::Listener* listener) {
   listeners_.AddWithID(listener, routing_id);
 }
 
 void MockRenderProcessHost::RemoveRoute(int32 routing_id) {
   DCHECK(listeners_.Lookup(routing_id) != NULL);
   listeners_.Remove(routing_id);
   Cleanup();
 }
 
+void MockRenderProcessHost::AddObserver(RenderProcessHostObserver* observer) {
+  NOTREACHED();
+}
+
+void MockRenderProcessHost::RemoveObserver(
+    RenderProcessHostObserver* observer) {
+  NOTREACHED();
+}
+
+bool MockRenderProcessHost::HasObserver(RenderProcessHostObserver* observer) {
+  NOTREACHED();
+  return false;
+}
+
 bool MockRenderProcessHost::WaitForBackingStoreMsg(
     int render_widget_id,
     const base::TimeDelta& max_delay,
     IPC::Message* msg) {
   return false;
 }
 
 void MockRenderProcessHost::ReceivedBadMessage() {
   ++bad_msg_count_;
 }
@@ skipping 193 matching lines @@
   for (ScopedVector<MockRenderProcessHost>::iterator it = processes_.begin();
        it != processes_.end(); ++it) {
     if (*it == host) {
       processes_.weak_erase(it);
       break;
     }
   }
 }
 
 }  // content