[Chromecast] Handle device scale factor correctly

chromecast/browser/cast_content_browser_client.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 "chromecast/browser/cast_content_browser_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 258 matching lines @@
   prefs->allow_scripts_to_close_windows = true;
   // TODO(lcwu): http://crbug.com/391089. This pref is set to true by default
   // because some content providers such as YouTube use plain http requests
   // to retrieve media data chunks while running in a https page. This pref
   // should be disabled once all the content providers are no longer doing that.
   prefs->allow_running_insecure_content = true;
 
   // Enable 5% margins for WebVTT cues to keep within title-safe area
   prefs->text_track_margin_percentage = 5;
 
-#if defined(OS_ANDROID)
+#if !defined(OS_ANDROID)

[alokp, 2016/05/11 21:48:47]

You might want to just set viewport_enabled and viewport_meta_enabled to true
without any OS_ANDROID guard and remove those DCHECKs.

+  // Viewport is only enabled by default on Android; we use it consistently
+  // across all platforms.
+  prefs->viewport_enabled = true;
+  prefs->viewport_meta_enabled = true;
+#endif
+
   // Enable the television style for viewport so that all cast apps have a
   // 1280px wide layout viewport by default.
   DCHECK(prefs->viewport_enabled);
   DCHECK(prefs->viewport_meta_enabled);
   prefs->viewport_style = content::ViewportStyle::TELEVISION;
-#endif  // defined(OS_ANDROID)
 }
 
 void CastContentBrowserClient::ResourceDispatcherHostCreated() {
   CastBrowserProcess::GetInstance()->SetResourceDispatcherHostDelegate(
       base::WrapUnique(new CastResourceDispatcherHostDelegate));
   content::ResourceDispatcherHost::Get()->SetDelegate(
       CastBrowserProcess::GetInstance()->resource_dispatcher_host_delegate());
 }
 
 std::string CastContentBrowserClient::GetApplicationLocale() {
@@ skipping 213 matching lines @@
         process_type, dumps_path, false /* upload */);
   // StartUploaderThread() even though upload is diferred.
   // Breakpad-related memory is freed in the uploader thread.
   crash_handler->StartUploaderThread();
   return crash_handler;
 }
 #endif  // !defined(OS_ANDROID)
 
 }  // namespace shell
 }  // namespace chromecast