Remove dependencies on extensions from content/browser/debugger.

content/browser/mock_content_browser_client.cc

Index: content/browser/mock_content_browser_client.cc
diff --git a/content/browser/mock_content_browser_client.cc b/content/browser/mock_content_browser_client.cc
index 59f7ccb7b9c23d7a7dbdf1f9e2fc17469d2ba3d2..6cf00df7f5c6d6787d5dc7964f80877016fd0571 100644
--- a/content/browser/mock_content_browser_client.cc
+++ b/content/browser/mock_content_browser_client.cc
@@ -183,6 +183,14 @@ bool MockContentBrowserClient::IsFastShutdownPossible() {
   return true;
 }
 
+void MockContentBrowserClient::RegisterDevToolsRemoteListeners(
+    DevToolsProtocolHandler* proto_handler) {
+}
+
+void MockContentBrowserClient::GetAdditionalStartPagesForDevTools(
+    TabContents* dev_tools_tab, ListValue* results) {
+}
+
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 int MockContentBrowserClient::GetCrashSignalFD(
     const std::string& process_type) {