Ensure that Metro chrome in ASH is able to connect to an existing desktop chrome AURA process.

chrome/test/base/testing_browser_process.cc

Index: chrome/test/base/testing_browser_process.cc
===================================================================
--- chrome/test/base/testing_browser_process.cc	(revision 169477)
+++ chrome/test/base/testing_browser_process.cc	(working copy)
@@ -285,6 +285,10 @@
 #endif
 }
 
+void TestingBrowserProcess::PlatformSpecificCommandLineProcessing(
+    const CommandLine& command_line) {
+}
+
 void TestingBrowserProcess::SetBookmarkPromptController(
     BookmarkPromptController* controller) {
 #if !defined(OS_IOS)