Enable VariationsService on Android.

BUG=224018, 168224
TEST=On a Chrome for Android official build, launch Chrome, quit it and launch it again. Go to chrome://version and verify that the string "5a3c10b5" appears in the Variations list. (This corresponds to the server-controlled Test0PercentDefault field trial).
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/13954011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195407 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chrome_browser_field_trials.cc

@@ -48,15 +48,19 @@ void ChromeBrowserFieldTrials::SetupFieldTrials(PrefService* local_state) {
   const base::Time install_time = base::Time::FromTimeT(
       local_state->GetInt64(prefs::kInstallDate));
   DCHECK(!install_time.is_null());
+
   chrome_variations::SetupUniformityFieldTrials(install_time);
   SetUpSimpleCacheFieldTrial();
+
 #if !defined(OS_ANDROID) && !defined(OS_IOS)
   SetupDesktopFieldTrials(local_state);
-#endif  // defined(OS_ANDROID)
+#endif  // !defined(OS_ANDROID) && !defined(OS_IOS)
 
 #if defined(OS_ANDROID) || defined(OS_IOS)
   SetupMobileFieldTrials();
 #endif  // defined(OS_ANDROID) || defined(OS_IOS)
+
+  InstantiateDynamicTrials();
 }
 
 
@@ -116,7 +120,6 @@ void ChromeBrowserFieldTrials::SetupDesktopFieldTrials(
 #if defined(ENABLE_ONE_CLICK_SIGNIN)
   OneClickSigninHelper::InitializeFieldTrial();
 #endif
-  InstantiateDynamicTrials();
   SetupAppLauncherFieldTrial(local_state);
 }
 

chrome/browser/chrome_browser_main.cc

@@ -1458,7 +1458,12 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
   // http://crbug.com/105065.
   browser_process_->notification_ui_manager();
 
-#if !defined(OS_ANDROID)
+#if defined(OS_ANDROID)
+  chrome_variations::VariationsService* variations_service =
+      browser_process_->variations_service();
+  if (variations_service)
+    variations_service->StartRepeatedVariationsSeedFetch();
+#else
   // Most general initialization is behind us, but opening a
   // tab and/or session restore and such is still to be done.
   base::TimeTicks browser_open_start = base::TimeTicks::Now();

chrome/browser/metrics/variations/variations_service.cc

@@ -251,8 +251,7 @@ void VariationsService::RegisterPrefs(PrefRegistrySimple* registry) {
 
 // static
 VariationsService* VariationsService::Create(PrefService* local_state) {
-// This is temporarily disabled for Android. See http://crbug.com/168224
-#if !defined(GOOGLE_CHROME_BUILD) || defined(OS_ANDROID)
+#if !defined(GOOGLE_CHROME_BUILD)
   // Unless the URL was provided, unsupported builds should return NULL to
   // indicate that the service should not be used.
   if (!CommandLine::ForCurrentProcess()->HasSwitch(

chrome/browser/prefs/browser_prefs.cc

@@ -204,6 +204,7 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
   SSLConfigServiceManager::RegisterPrefs(registry);
   UpgradeDetector::RegisterPrefs(registry);
   WebCacheManager::RegisterPrefs(registry);
+  chrome_variations::VariationsService::RegisterPrefs(registry);
 
 #if defined(ENABLE_PLUGINS)
   PluginFinder::RegisterPrefs(registry);
@@ -233,7 +234,6 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
 
 #if !defined(OS_ANDROID)
   BackgroundModeManager::RegisterPrefs(registry);
-  chrome_variations::VariationsService::RegisterPrefs(registry);
   RegisterBrowserPrefs(registry);
   RegisterDefaultBrowserPromptPrefs(registry);
   ManagedMode::RegisterPrefs(registry);