Enable new session crashed bubble UI by Finch experiment.

chrome/browser/ui/views/session_crashed_bubble_view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/session_crashed_bubble_view.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/sessions/session_restore.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_list_observer.h"
 #include "chrome/browser/ui/options/options_util.h"
 #include "chrome/browser/ui/startup/session_crashed_bubble.h"
 #include "chrome/browser/ui/startup/startup_browser_creator_impl.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/toolbar/toolbar_view.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/google_chrome_strings.h"
@@ skipping 21 matching lines @@
 
 // Margins width for the top rows to compensate for the bottom panel for which
 // we don't want any margin.
 const int kMarginWidth = 12;
 const int kMarginHeight = kMarginWidth;
 
 // The color of the background of the sub panel to offer UMA optin.
 const SkColor kLightGrayBackgroundColor = 0xFFF0F0F0;
 const SkColor kWhiteBackgroundColor = 0xFFFFFFFF;
 
+// The Finch study name and group name that enables session crashed bubble UI.
+const char kEnableBubbleUIFinchName[] = "EnableSessionCrashedBubbleUI";
+const char kEnableBubbleUIGroupEnabled[] = "Enabled";
+
 bool ShouldOfferMetricsReporting() {
 // Stats collection only applies to Google Chrome builds.
 #if defined(GOOGLE_CHROME_BUILD)
   // Only show metrics reporting option if user didn't already consent to it.
   if (GoogleUpdateSettings::GetCollectStatsConsent())
     return false;
   return g_browser_process->local_state()->FindPreference(
       prefs::kMetricsReportingEnabled)->IsUserModifiable();
 #else
   return false;
 #endif  // defined(GOOGLE_CHROME_BUILD)
 }
 
+// Whether or not the bubble UI should be used.
+bool IsBubbleUIEnabled() {
+  const std::string group_name = base::FieldTrialList::FindFullName(
+      kEnableBubbleUIFinchName);
+  if (CommandLine::ForCurrentProcess()->HasSwitch(

[Alexei Svitkine (slow), 2014/05/27 16:53:10]

Nit: extract to a local var so you don't need to wrap the ifs:

  const base::CommandLine& command_line = *CommandLine::ForCurrentProcess();
  if (command_line->HasSwitch(switches::kDisableSessionCrashedBubble))
    return false;
  ...

[yao, 2014/05/27 17:22:49]

Done.

+          switches::kDisableSessionCrashedBubble))
+    return false;
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableSessionCrashedBubble))
+    return true;
+  return group_name == kEnableBubbleUIGroupEnabled;
+}
+
 }  // namespace
 
 // A helper class that listens to browser removal event.
 class SessionCrashedBubbleView::BrowserRemovalObserver
     : public chrome::BrowserListObserver {
  public:
   explicit BrowserRemovalObserver(Browser* browser);
   virtual ~BrowserRemovalObserver();
 
   // Overridden from chrome::BrowserListObserver.
@@ skipping 323 matching lines @@
         prefs::kMetricsReportingEnabled, true);
   }
   CloseBubble();
 }
 
 void SessionCrashedBubbleView::CloseBubble() {
   GetWidget()->Close();
 }
 
 bool ShowSessionCrashedBubble(Browser* browser) {
-  SessionCrashedBubbleView::Show(browser);
-  return true;
+  if (IsBubbleUIEnabled()) {
+    SessionCrashedBubbleView::Show(browser);
+    return true;
+  }
+  return false;
 }