[Chromecast] Adding pause/resume operations to VideoPlaneController.

chromecast/base/cast_resource.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_BASE_CAST_RESOURCE_H_
 #define CHROMECAST_BASE_CAST_RESOURCE_H_
 
 #include "base/macros.h"
 
 namespace chromecast {
 
 // Interface for resources needed to run application.
 class CastResource {

[byungchul, 2015/12/18 00:53:21]

Can we rename this as CastResourceContainer or something? It's getting
confusing.

[esum, 2015/12/21 00:39:21]

Agreed. Doing later in another CL though since the CastResource class gets used
a bunch of different places. Made b/26279969.

  public:
   // Resources necessary to run cast apps. CastResource may contain union of the
   // following types.
   // TODO(yucliu): Split video resources and graphic resources.
   enum Resource {
     kResourceNone = 0,
     // All resources necessary to render sounds, for example, audio pipeline,
     // speaker, etc.
     kResourceAudio = 1 << 0,
     // All resources necessary to render videos or images, for example, video
@@ skipping 22 matching lines @@
     //            returned, Client will remove the resource from its watching
     //            list.
     virtual void OnResourceReleased(CastResource* cast_resource,
                                     Resource remain) = 0;
 
    protected:
     virtual ~Client() {}
   };
 
   void SetCastResourceClient(Client* client);
+  // Called to initialize resources after OEM has granted them, and before
+  // they start getting used by consumers. Implementation must be synchronous
+  // since consumers will start using the resource immediately afterwards.
+  // TODO(esum): We should allow this method to be asynchronous in case an
+  // implementer needs to make expensive calls and doesn't want to block the
+  // UI thread (b/26239576). For now, don't do anything expensive in your
+  // implementation; if you really need to, then this bug has to be resolved.
+  virtual void InitializeResource(Resource resource) = 0;

[byungchul, 2015/12/18 00:53:21]

GrantResource?

[esum, 2015/12/21 00:39:21]

I actually prefer InitializeResource since this serves a different purpose than
OEM's granting resources to cast. If we call this GrantResource too, it would
get confusing IMO.

[derekjchow1, 2016/01/04 17:29:10]

How about AcquireResource, since this is the opposite of ReleaseResource?
Alternatively, we can rename ReleaseResource DeinitializeResource.

[esum, 2016/01/11 16:28:57]

Done. Had to rearrange some names to make things clearer. Discussed with Yuchen
offline just to be sure.

   // Called to release resources. Implementation should call
   // Client::OnResourceReleased when resource is released on its side.
   virtual void ReleaseResource(Resource resource) = 0;
 
  protected:
   CastResource() : client_(nullptr) {}
   virtual ~CastResource() {}
 
   void NotifyResourceAcquired();
   void NotifyResourceReleased(Resource remain);
 
  private:
   Client* client_;
 
   DISALLOW_COPY_AND_ASSIGN(CastResource);
 };
 
 }  // namespace chromecast
 
 #endif