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

content/shell/shell_content_client.h

Index: content/shell/shell_content_client.h
===================================================================
--- content/shell/shell_content_client.h	(revision 133033)
+++ content/shell/shell_content_client.h	(working copy)
@@ -6,6 +6,9 @@
 #define CONTENT_SHELL_SHELL_CONTENT_CLIENT_H_
 #pragma once
 
+#include <string>
+#include <vector>
+
 #include "base/compiler_specific.h"
 #include "content/public/common/content_client.h"
 
@@ -21,6 +24,9 @@
       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;