Get chrome:// dev tool urls hooked up in content_shell.

content/test/test_content_client.h

 // 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.
 
 #ifndef CONTENT_TEST_TEST_CONTENT_CLIENT_H_
 #define CONTENT_TEST_TEST_CONTENT_CLIENT_H_
 #pragma once
 
+#include <string>
+#include <vector>
+
 #include "base/compiler_specific.h"
 #include "content/public/common/content_client.h"
 #include "ui/base/resource/data_pack.h"
 
 class TestContentClient : public content::ContentClient {
  public:
   TestContentClient();
   virtual ~TestContentClient();
 
   // content::ContentClient:
   virtual void SetActiveURL(const GURL& url) OVERRIDE;
   virtual void SetGpuInfo(const content::GPUInfo& gpu_info) OVERRIDE;
   virtual void AddPepperPlugins(
       std::vector<content::PepperPluginInfo>* plugins) OVERRIDE;
   virtual void AddNPAPIPlugins(
       webkit::npapi::PluginList* plugin_list) OVERRIDE;
+  virtual void AddAdditionalSchemes(
+      std::vector<std::string>* standard_schemes,
+      std::vector<std::string>* savable_schemes) OVERRIDE;
   virtual bool HasWebUIScheme(const GURL& url) const OVERRIDE;
   virtual bool CanHandleWhileSwappedOut(const IPC::Message& msg) OVERRIDE;
   virtual std::string GetUserAgent() const OVERRIDE;
   virtual string16 GetLocalizedString(int message_id) const OVERRIDE;
   virtual base::StringPiece GetDataResource(int resource_id) const OVERRIDE;
 #if defined(OS_WIN)
   virtual bool SandboxPlugin(CommandLine* command_line,
                              sandbox::TargetPolicy* policy) OVERRIDE;
 #endif
 #if defined(OS_MACOSX)
   virtual bool GetSandboxProfileForSandboxType(
       int sandbox_type,
       int* sandbox_profile_resource_id) const OVERRIDE;
 #endif
 
  private:
   ui::DataPack data_pack_;
 
   DISALLOW_COPY_AND_ASSIGN(TestContentClient);
 };
 
 #endif  // CONTENT_TEST_TEST_CONTENT_CLIENT_H_