Adds --file-manager-new-ui to chrome://flags.

This patch adds the flags to chrome://flags to make it possible to enable it on chromebooks without tricks.

TEST=Enable the Files.app new UI feature. Check if the Files.app launches with the new ui.
BUG=226904

Review URL: https://chromiumcodereview.appspot.com/14345002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194920 0039d316-1c4b-4281-b951-d872f2087c98

chrome/app/generated_resources.grd

@@ -12139,6 +12139,12 @@ Some features may be unavailable.  Please check that the profile exists and you
       <message name="IDS_FLAGS_FILE_MANAGER_LEGACY_DESCRIPTION" desc="Description of about:flag option to launch the Files app in the legacy mode.">
         Run Files app as an extension instead of a platform app.
       </message>
+      <message name="IDS_FLAGS_FILE_MANAGER_NEW_UI_NAME" desc="Name of about:flag option to launch the Files app with the new experimental ui.">
+        Files.app's new UI
+      </message>
+      <message name="IDS_FLAGS_FILE_MANAGER_NEW_UI_DESCRIPTION" desc="Description of about:flag option to launch the Files app with the new experimental ui.">
+        Run Files app with the new experimental user interface.
+      </message>
       <message name="IDS_FILE_BROWSER_ROOT_DIRECTORY_LABEL" desc="Root directory label.">
         Files
       </message>

chrome/browser/about_flags.cc

@@ -1031,6 +1031,13 @@ const Experiment kExperiments[] = {
     kOsCrOS,
     SINGLE_VALUE_TYPE(switches::kFileManagerLegacy),
   },
+  {
+    "file-manager-new-ui",
+    IDS_FLAGS_FILE_MANAGER_NEW_UI_NAME,
+    IDS_FLAGS_FILE_MANAGER_NEW_UI_DESCRIPTION,
+    kOsCrOS,
+    SINGLE_VALUE_TYPE(switches::kFileManagerNewUI),
+  },
   {
     "disable-launcher-per-display",
     IDS_FLAGS_DISABLE_LAUNCHER_PER_DISPLAY_NAME,