[fuchsia] Provide an ApplicationController.GetMediaPlayer() API.

Allow media playback in CastComponents to be controlled by the owning
Agent.

Bug: 879317
Change-Id: I6a744faa0b236f3a856d5c4aa0b9f0846f6970ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2130546
Commit-Queue: Wez <wez@chromium.org>
Auto-Submit: Wez <wez@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756346}

fuchsia/BUILD.gn

@@ -20,6 +20,7 @@ fidl_library("cast_fidl") {
   ]
 
   public_deps = [
+    "//third_party/fuchsia-sdk/sdk/fidl/fuchsia.media.sessions2",
     "//third_party/fuchsia-sdk/sdk/fidl/fuchsia.ui.gfx",
     "//third_party/fuchsia-sdk/sdk/fidl/fuchsia.web",
   ]

fuchsia/fidl/cast/application_controller.fidl

@@ -4,9 +4,14 @@
 
 library chromium.cast;
 
+using fuchsia.media.sessions2;
+
 /// Allows clients to access and modify certain aspects of the Cast receiver
 /// application runtime.
 protocol ApplicationController {
   /// Enables or disables touch event processing.
   SetTouchInputEnabled(bool enable);
+
+  /// Connects to the application's media control & observation API.
+  GetMediaPlayer(request<fuchsia.media.sessions2.Player> request);
 };

fuchsia/runners/cast/application_controller_impl.cc

@@ -31,3 +31,8 @@ void ApplicationControllerImpl::SetTouchInputEnabled(bool enable) {
                               (enable ? fuchsia::web::AllowInputState::ALLOW
                                       : fuchsia::web::AllowInputState::DENY));
 }
+
+void ApplicationControllerImpl::GetMediaPlayer(
+    fidl::InterfaceRequest<fuchsia::media::sessions2::Player> request) {
+  frame_->GetMediaPlayer(std::move(request));
+}

fuchsia/runners/cast/application_controller_impl.h

@@ -5,8 +5,10 @@
 #ifndef FUCHSIA_RUNNERS_CAST_APPLICATION_CONTROLLER_IMPL_H_
 #define FUCHSIA_RUNNERS_CAST_APPLICATION_CONTROLLER_IMPL_H_
 
+#include <fuchsia/media/sessions2/cpp/fidl.h>
 #include <fuchsia/web/cpp/fidl.h>
 #include <lib/fidl/cpp/binding.h>
+#include <lib/fidl/cpp/interface_request.h>
 
 #include "base/macros.h"
 #include "fuchsia/fidl/chromium/cast/cpp/fidl.h"
@@ -19,7 +21,10 @@ class ApplicationControllerImpl : public chromium::cast::ApplicationController {
   ~ApplicationControllerImpl() final;
 
  protected:
-  void SetTouchInputEnabled(bool enable) override;
+  void SetTouchInputEnabled(bool enable) final;
+  void GetMediaPlayer(
+      ::fidl::InterfaceRequest<fuchsia::media::sessions2::Player> request)
+      final;
 
  private:
   fidl::Binding<chromium::cast::ApplicationController> binding_;