DevTools: add support for chrome-devtools://devtools/remote/open? URL.

chrome/browser/devtools/devtools_ui_bindings.cc

 // Copyright 2014 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 "chrome/browser/devtools/devtools_ui_bindings.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 776 matching lines @@
     results.Append(extension_info);
   }
   CallClientFunction("WebInspector.addExtensions", &results, NULL, NULL);
 }
 
 void DevToolsUIBindings::SetDelegate(Delegate* delegate) {
   delegate_.reset(delegate);
 }
 
 void DevToolsUIBindings::AttachTo(content::DevToolsAgentHost* agent_host) {
-  DCHECK(!agent_host_);
+  if (agent_host_)
+    Detach();
   agent_host_ = agent_host;
   agent_host_->AttachClient(this);
 }
 
 void DevToolsUIBindings::Reattach() {
   DCHECK(agent_host_);
   agent_host_->DetachClient();
   agent_host_->AttachClient(this);
 }
 
 void DevToolsUIBindings::Detach() {
-  DCHECK(agent_host_);
-  agent_host_->DetachClient();
+  if (agent_host_)
+    agent_host_->DetachClient();
   agent_host_ = NULL;
 }
 
 bool DevToolsUIBindings::IsAttachedTo(content::DevToolsAgentHost* agent_host) {
   return agent_host_ == agent_host;
 }
 
 void DevToolsUIBindings::CallClientFunction(const std::string& function_name,
                                             const base::Value* arg1,
                                             const base::Value* arg2,
@@ skipping 18 matching lines @@
   web_contents_->GetMainFrame()->ExecuteJavaScript(javascript);
 }
 
 void DevToolsUIBindings::DocumentOnLoadCompletedInMainFrame() {
   // Call delegate first - it seeds importants bit of information.
   delegate_->OnLoadCompleted();
 
   UpdateTheme();
   AddDevToolsExtensionsToClient();
 }