Adds new libcast_media shared library for cast_shell media

chromecast/public/cast_media_shlib.h

+// Copyright 2015 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.
+
+#ifndef CHROMECAST_PUBLIC_CAST_MEDIA_SHLIB_H_
+#define CHROMECAST_PUBLIC_CAST_MEDIA_SHLIB_H_
+
+#include <string>
+#include <vector>
+
+#include "chromecast_export.h"
+
+namespace chromecast {
+
+class CHROMECAST_EXPORT CastMediaShlib {
+ public:
+  // Performs platform-specific one-time initialization for media systems and
+  // hardware resources. Called at startup in browser process before main

[gunsch, 2015/05/13 03:26:04]

I think references to "browser process" here are inappropriate; this can also be
called in cases such as unit test startup, no?

[halliwell, 2015/05/13 03:43:33]

True that it can be called in unit tests, but remember these comments are for
vendors, this is our API documentation.  I actually think it's critical that we
document which processes they can expect their APIs to be called in.  For
example, I'm unhappy with the graphics egl platform class, which gets
instantiated both in the browser and the GPU process, and a subset of the
functions get called in each case.  This is something we kind of inherited from
Ozone, not something we designed that way, but still it sucks.  The vendor has
to make sure not to initialise any GL stuff when they're called in the browser
process.  My plan there is to separate that into two APIs, one for each process.

For media, there is going to be stuff happening in the renderer and stuff
happening in the browser, and theoretically one could imagine doing stuff in the
gpu process one day.  I think it's important to be clear about that.

+  // message loop begins.
+  static void Initialize(const std::vector<std::string>& argv);
+
+  // Performs platform-specific one-time teardown of media systems and hardware
+  // resources. Called at browser process exit.
+  static void Finalize();
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_PUBLIC_CAST_MEDIA_SHLIB_H_