ChromeOS: Enable Gaia v2 API by default.

BUG=709244

Review-Url: https://codereview.chromium.org/2970463002
Cr-Original-Commit-Position: refs/heads/master@{#483877}
Committed: https://chromium.googlesource.com/chromium/src/+/30815d143e71eb731bea80ba5fbd236d628ee9f3
Review-Url: https://codereview.chromium.org/2970463002
Cr-Commit-Position: refs/heads/master@{#486617}

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

@@ -352,12 +352,15 @@ void GaiaScreenHandler::LoadGaiaWithVersion(
     params.SetString("gaiaPath", eafe_path);
   }
 
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kCrosGaiaApiV1)) {
-    params.SetString("chromeOSApiVersion", "1");
-  } else if (use_easy_bootstrap_) {
   // Easy bootstrap is not v2-compatible
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kCrosGaiaApiV1) ||
+      use_easy_bootstrap_) {
     params.SetString("chromeOSApiVersion", "1");
+  } else {
+    // This enables GLIF MM UI for the online Gaia screen by default.
+    // (see https://crbug.com/709244 ).
+    params.SetString("chromeOSApiVersion", "2");
   }
 
   frame_state_ = FRAME_STATE_LOADING;