Restoring the chrome variatioons client, with a fix for browser_test failures caused by it.

chrome/test/base/testing_browser_process.h

Index: chrome/test/base/testing_browser_process.h
diff --git a/chrome/test/base/testing_browser_process.h b/chrome/test/base/testing_browser_process.h
index 87110ca01f4d59f6106cac0c05301bd2994d03f6..260ceecae00c5d5ec0e67064f48b106849aa5983 100644
--- a/chrome/test/base/testing_browser_process.h
+++ b/chrome/test/base/testing_browser_process.h
@@ -55,6 +55,7 @@ class TestingBrowserProcess : public BrowserProcess {
   virtual WatchDogThread* watchdog_thread() OVERRIDE;
   virtual ProfileManager* profile_manager() OVERRIDE;
   virtual PrefService* local_state() OVERRIDE;
+  virtual VariationsService* variations_service() OVERRIDE;
   virtual policy::BrowserPolicyConnector* browser_policy_connector() OVERRIDE;
   virtual policy::PolicyService* policy_service() OVERRIDE;
   virtual IconManager* icon_manager() OVERRIDE;