DevTools: complete 2-sided migration to attach w/ id (content)

Review URL: https://codereview.chromium.org/345113004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278797 0039d316-1c4b-4281-b951-d872f2087c98

content/renderer/devtools/devtools_agent.cc

@@ -121,10 +121,6 @@ void DevToolsAgent::sendMessageToInspectorFrontend(
                                                          message.utf8()));
 }
 
-int DevToolsAgent::hostIdentifier() {
-  return routing_id();
-}
-
 int DevToolsAgent::debuggerId() {
   return routing_id();
 }

content/renderer/devtools/devtools_agent.h

@@ -50,7 +50,6 @@ class DevToolsAgent : public RenderViewObserver,
   // WebDevToolsAgentClient implementation
   virtual void sendMessageToInspectorFrontend(const blink::WebString& data);
 
-  virtual int hostIdentifier() OVERRIDE;
   virtual int debuggerId() OVERRIDE;
   virtual void saveAgentRuntimeState(const blink::WebString& state) OVERRIDE;
   virtual blink::WebDevToolsAgentClient::WebKitClientMessageLoop*