Flip the flag and enable MTP support by default.

The --enable-filemanager-mtp is now on by default.
It can still be disabled by --enable-filemanager-mtp=false, or
choosing "disabled" in about:flags.

BUG=266939

Review URL: https://codereview.chromium.org/314033002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275375 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/about_flags.cc

@@ -427,6 +427,16 @@ const Experiment::Choice kMalwareInterstitialVersions[] = {
     switches::kMalwareInterstitialVersionV3, "" },
 };
 
+#if defined(OS_CHROMEOS)
+const Experiment::Choice kEnableFileManagerMTPChoices[] = {
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_ENABLED,
+    chromeos::switches::kEnableFileManagerMTP, "true" },
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DISABLED,
+    chromeos::switches::kEnableFileManagerMTP, "false" }
+};
+#endif
+
 // RECORDING USER METRICS FOR FLAGS:
 // -----------------------------------------------------------------------------
 // The first line of the experiment is the internal name. If you'd like to
@@ -1784,7 +1794,7 @@ const Experiment kExperiments[] = {
     IDS_FLAGS_ENABLE_FILE_MANAGER_MTP_NAME,
     IDS_FLAGS_ENABLE_FILE_MANAGER_MTP_DESCRIPTION,
     kOsCrOS,
-    SINGLE_VALUE_TYPE(chromeos::switches::kEnableFileManagerMTP)
+    MULTI_VALUE_TYPE(kEnableFileManagerMTPChoices)
   },
 #endif
   // TODO(tyoshino): Remove this temporary flag and command line switch. See

chrome/browser/chromeos/file_manager/volume_manager.cc

@@ -395,9 +395,10 @@ void VolumeManager::Initialize() {
   }
 
   // Subscribe to storage monitor for MTP notifications.
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-          chromeos::switches::kEnableFileManagerMTP) &&
-      storage_monitor::StorageMonitor::GetInstance()) {
+  const bool disable_mtp =
+      CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          chromeos::switches::kEnableFileManagerMTP) == "false";
+  if (!disable_mtp && storage_monitor::StorageMonitor::GetInstance()) {
     storage_monitor::StorageMonitor::GetInstance()->EnsureInitialized(
         base::Bind(&VolumeManager::OnStorageMonitorInitialized,
                    weak_ptr_factory_.GetWeakPtr()));