Add an about:flag to control WebApk enablement.

chrome/browser/android/shortcut_helper.cc

 // Copyright 2013 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/android/shortcut_helper.h"
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
@@ skipping 56 matching lines @@
 void ShortcutHelper::AddToLauncherInBackgroundWithSkBitmap(
     content::BrowserContext* browser_context,
     const ShortcutInfo& info,
     const std::string& webapp_id,
     const SkBitmap& icon_bitmap,
     const base::Closure& splash_image_callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
   if (info.display == blink::WebDisplayModeStandalone ||
       info.display == blink::WebDisplayModeFullscreen) {
-    if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kEnableWebApk)) {
+    JNIEnv* env = base::android::AttachCurrentThread();
+    if (Java_ShortcutHelper_areWebApksEnabled(env)) {
       InstallWebApkInBackgroundWithSkBitmap(browser_context, info, icon_bitmap);
       return;
     }
     AddWebappInBackgroundWithSkBitmap(info, webapp_id, icon_bitmap,
                                       splash_image_callback);
     return;
   }
   AddShortcutInBackgroundWithSkBitmap(info, icon_bitmap);
 }
 
@@ skipping 217 matching lines @@
   DCHECK(jsplash_image_callback);
   base::Closure* splash_image_callback =
       reinterpret_cast<base::Closure*>(jsplash_image_callback);
   splash_image_callback->Run();
   delete splash_image_callback;
 }
 
 bool ShortcutHelper::RegisterShortcutHelper(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }