DevTools: introduce --custom-devtools-frontend flag.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index 35cb84132de1cc62bf91b21814252f9bcb89d284..fcf62c7789a206feb64b5d00a978e42fd789d1d7 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -145,6 +145,10 @@ const char kCrashOnHangThreads[]            = "crash-on-hang-threads";
 const char kCreateBrowserOnStartupForTests[] =
     "create-browser-on-startup-for-tests";
 
+// Specifies the HTTP endpoint which will be used to serve
+// chrome-devtools://devtools/custom/<path>
+const char kCustomDevtoolsFrontend[] = "custom-devtools-frontend";
+
 // Enables a frame context menu item that toggles the frame in and out of glass
 // mode (Windows Vista and up only).
 const char kDebugEnableFrameToggle[]        = "debug-enable-frame-toggle";