Fixes bug where cast_shell uses fraction of screen on ATV

chromecast/renderer/cast_content_renderer_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/renderer/cast_content_renderer_client.h"
 
 #include <sys/sysinfo.h>
 
 #include "base/command_line.h"
 #include "base/memory/memory_pressure_listener.h"
@@ skipping 129 matching lines @@
     content::RenderView* render_view) {
   blink::WebView* webview = render_view->GetWebView();
   if (webview) {
     webview->setBaseBackgroundColor(kColorBlack);
 
     // The following settings express consistent behaviors across Cast
     // embedders, though Android has enabled by default for mobile browsers.
     webview->settings()->setShrinksViewportContentToFit(false);
     webview->settings()->setMediaControlsOverlayPlayButtonEnabled(false);
 
+    // Scale 1 ensures window.innerHeight/Width match application resolution.
+    // PageScaleOverride is the 'user agent' value which overrides page
+    // settings (from meta viewport tag) - thus preventing inconsistency
+    // between Android and non-Android cast_shell.
+    webview->setDefaultPageScaleLimits(1.f, 1.f);
+    webview->setInitialPageScaleOverride(1.f);

[lcwu1, 2015/04/24 00:54:21]

Do we need both? ISTM the first API call should be able to restore the behavior
on M41. And if we don't make the first call, the 2nd API call should be able to
override the default scale setting.

[halliwell, 2015/04/24 01:02:38]

I believe we want the second call to override the meta viewport tag.  If we
don't do this, we will get inconsistent behaviour between ATV and other
platforms (where meta viewport is ignored).

I think you may be right that we don't need the first call though.  I will
check.

[lcwu1, 2015/04/24 01:05:58]

This sounds correct to me, as the order seems to be:

1. default scale
2. page scale (meta viewport)
3. override

So doing #3 (which is your 2nd API) should be good enough. But please do
try/test it out.

[halliwell, 2015/04/27 17:44:20]

I tried this, and it does work (setting initial scale only).  However, I think
there's an argument for setting the min/max as well.  In principle, the override
value is only an _initial_ override, and Blink is free to change it within the
min/max range according to its logic.  In practice, it probably only changes it
based on pinch/zoom events, but still, if we want to fix the page scale at 1, it
seems correct to also set the min/max range.

Let me know if you agree or not :)

+
     // Disable application cache as Chromecast doesn't support off-line
     // application running.
     webview->settings()->setOfflineWebApplicationCacheEnabled(false);
   }
 
   // Note: RenderView will own the lifetime of its observer.
   new CastRenderViewObserver(render_view);
 }
 
 void CastContentRendererClient::AddKeySystems(
@@ skipping 29 matching lines @@
     closure.Run();
     return;
   }
 
   // Lifetime is tied to |render_frame| via content::RenderFrameObserver.
   new CastMediaLoadDeferrer(render_frame, closure);
 }
 
 }  // namespace shell
 }  // namespace chromecast