Implements extensions devtools API

chrome/test/testing_profile.h

Index: chrome/test/testing_profile.h
diff --git a/chrome/test/testing_profile.h b/chrome/test/testing_profile.h
index eb58bf4b1bd7469da4acd8d6d34226c1f10aac0d..ecfec353771c6ab853630ac3a56933a3c31bcfc8 100644
--- a/chrome/test/testing_profile.h
+++ b/chrome/test/testing_profile.h
@@ -83,6 +83,9 @@ class TestingProfile : public Profile {
   virtual UserScriptMaster* GetUserScriptMaster() {
     return NULL;
   }
+  virtual ExtensionDevToolsManager* GetExtensionDevToolsManager() {
+    return NULL;
+  }
   virtual ExtensionProcessManager* GetExtensionProcessManager() {
     return NULL;
   }