Use correct namespace in variations component

The componentization of //chrome/browser/metrics/variations is complete. This
CL changes all code in //components/variations to use the variations namespace
instead of the chrome_variations namespace.

BUG=516685
TBR=thakis

Review URL: https://codereview.chromium.org/1324733002

Cr-Commit-Position: refs/heads/master@{#347361}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 2e24400..426d7bf 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -244,7 +244,7 @@
   ChromeMetricsServiceClient::RegisterPrefs(registry);
   ChromeTracingDelegate::RegisterPrefs(registry);
   chrome_prefs::RegisterPrefs(registry);
-  chrome_variations::VariationsService::RegisterPrefs(registry);
+  variations::VariationsService::RegisterPrefs(registry);
   component_updater::RegisterPrefsForRecoveryComponent(registry);
   component_updater::SupervisedUserWhitelistInstaller::RegisterPrefs(registry);
   ExternalProtocolHandler::RegisterPrefs(registry);
@@ -463,7 +463,7 @@
 #endif
 
 #if defined(OS_ANDROID)
-  chrome_variations::VariationsService::RegisterProfilePrefs(registry);
+  variations::VariationsService::RegisterProfilePrefs(registry);
   NewTabPagePrefs::RegisterProfilePrefs(registry);
   PartnerBookmarksShim::RegisterProfilePrefs(registry);
 #else