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

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 948b9cca8790f4111bddf76453105e6dff9b0411..33efb930890dcea38789a53f511f8d7867701e02 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -31,6 +31,7 @@
         'syncapi_service',
         'feedback_proto',
         'gdata_proto',
+        'variations_seed_proto',
         '../build/temp_gyp/googleurl.gyp:googleurl',
         '../content/content.gyp:content_browser',
         '../crypto/crypto.gyp:crypto',
@@ -1358,6 +1359,8 @@
         'browser/metrics/tracking_synchronizer.cc',
         'browser/metrics/tracking_synchronizer.h',
         'browser/metrics/tracking_synchronizer_observer.h',
+        'browser/metrics/variations_service.cc',
+        'browser/metrics/variations_service.h',
         'browser/native_window_notification_source.h',
         'browser/net/chrome_cookie_notification_details.h',
         'browser/net/chrome_fraudulent_certificate_reporter.cc',
@@ -5045,5 +5048,19 @@
       },
       'includes': [ '../build/protoc.gypi' ]
     },
+    {
+      # Protobuf compiler / generator for Chrome Variations seed.
+      'target_name': 'variations_seed_proto',
+      'type': 'static_library',
+      'sources': [ 
+        'browser/metrics/proto/trials_seed.proto',
+        'browser/metrics/proto/study.proto',
+      ],
+      'variables': {
+        'proto_in_dir': 'browser/metrics/proto',
+        'proto_out_dir': 'chrome/browser/metrics/proto',
+      },
+      'includes': [ '../build/protoc.gypi' ]
+    },
   ],
 }