Control permission bubbles with Finch flag

chrome/browser/ui/website_settings/permission_bubble_manager.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/website_settings/permission_bubble_manager.h"
 
 #include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/user_metrics_action.h"
 #include "chrome/browser/ui/website_settings/permission_bubble_request.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/user_metrics.h"
 
 namespace {
 
+// String constants to control whether bubbles are enabled by default.
+const char kTrialName[] = "PermissionBubbleRollout";
+const char kEnabled[] = "Enabled";
+const char kDisabled[] = "Disabled";
+
 class CancelledRequest : public PermissionBubbleRequest {
  public:
   explicit CancelledRequest(PermissionBubbleRequest* cancelled)
       : icon_(cancelled->GetIconID()),
         message_text_(cancelled->GetMessageText()),
         message_fragment_(cancelled->GetMessageTextFragment()),
         user_gesture_(cancelled->HasUserGesture()),
         hostname_(cancelled->GetRequestingHostname()) {}
   ~CancelledRequest() override {}
 
@@ skipping 19 matching lines @@
   bool user_gesture_;
   GURL hostname_;
 };
 
 }  // namespace
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(PermissionBubbleManager);
 
 // static
 bool PermissionBubbleManager::Enabled() {
+  // Command line flags take precedence.
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnablePermissionsBubbles))
     return true;
-
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisablePermissionsBubbles))
     return false;
 
+  std::string group(base::FieldTrialList::FindFullName(kTrialName));
+  if (group == kEnabled)
+    return true;
+  if (group == kDisabled)
+    return false;
+
   return false;
 }
 
 PermissionBubbleManager::PermissionBubbleManager(
     content::WebContents* web_contents)
   : content::WebContentsObserver(web_contents),
     require_user_gesture_(false),
     bubble_showing_(false),
     view_(NULL),
     request_url_has_loaded_(false),
@@ skipping 328 matching lines @@
 bool PermissionBubbleManager::HasUserGestureRequest(
     const std::vector<PermissionBubbleRequest*>& queue) {
   std::vector<PermissionBubbleRequest*>::const_iterator iter;
   for (iter = queue.begin(); iter != queue.end(); iter++) {
     if ((*iter)->HasUserGesture())
       return true;
   }
   return false;
 }