GMC: Allow recipient of OnAudioOutputSinkChanged IPC to translate device id

In order for the global media controls dialog to display the currently
used audio device in the UI the renderer needs to report what device is
in use. Currently, MediaWebContentsObserver will receive messages when
the output device is switched. However, the device id reported by the
renderer is hashed so that it may be only used on one origin.

This change has the MediaWebContentsObserver translate the device ID
before passing it off to the MediaSessionControllersManager.

Bug: 1111432
Change-Id: I11d161ff5f89525b4c465f01a779bdd30e31c823
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2331330
Commit-Queue: Noah Rose Ledesma <noahrose@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Tommy Steimel <steimel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795175}

content/browser/media/media_web_contents_observer.cc

@@ -7,9 +7,13 @@
 #include <memory>
 #include <tuple>
 
+#include "base/bind.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "build/build_config.h"
 #include "content/browser/media/audible_metrics.h"
 #include "content/browser/media/audio_stream_monitor.h"
+#include "content/browser/media/media_devices_util.h"
+#include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/media/media_player_delegate_messages.h"
 #include "content/public/browser/render_frame_host.h"
@@ -18,6 +22,7 @@
 #include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "services/device/public/mojom/wake_lock_context.mojom.h"
 #include "services/media_session/public/cpp/media_position.h"
+#include "third_party/blink/public/common/mediastream/media_devices.h"
 #include "third_party/blink/public/platform/web_fullscreen_video_status.h"
 #include "ui/gfx/geometry/size.h"
 
@@ -381,10 +386,49 @@ void MediaWebContentsObserver::OnAudioOutputSinkChanged(
     RenderFrameHost* render_frame_host,
     int delegate_id,
     std::string hashed_device_id) {
-  // TODO(1111432): Translate |hashed_device_id| into a raw device id before
-  // passing to controllers manager.
-  session_controllers_manager_.OnAudioOutputSinkChanged(
-      MediaPlayerId(render_frame_host, delegate_id), hashed_device_id);
+  auto salt_and_origin = content::GetMediaDeviceSaltAndOrigin(
+      render_frame_host->GetProcess()->GetID(),
+      render_frame_host->GetRoutingID());
+
+  auto callback_on_io_thread = base::BindOnce(
+      [](const std::string& salt, const url::Origin& origin,
+         const std::string& hashed_device_id,
+         base::OnceCallback<void(const base::Optional<std::string>&)>
+             callback) {
+        MediaStreamManager::GetMediaDeviceIDForHMAC(
+            blink::MediaDeviceType::MEDIA_DEVICE_TYPE_AUDIO_OUTPUT, salt,
+            std::move(origin), hashed_device_id,
+            base::SequencedTaskRunnerHandle::Get(), std::move(callback));
+      },
+      salt_and_origin.device_id_salt, std::move(salt_and_origin.origin),
+      hashed_device_id,
+      base::BindOnce(&MediaWebContentsObserver::OnAudioOutputDeviceIdTranslated,
+                     weak_ptr_factory_.GetWeakPtr(), render_frame_host,
+                     delegate_id));
+
+  content::GetIOThreadTaskRunner({})->PostTask(
+      FROM_HERE, std::move(callback_on_io_thread));
+}
+
+void MediaWebContentsObserver::OnAudioOutputDeviceIdTranslated(
+    RenderFrameHost* render_frame_host,
+    int delegate_id,
+    const base::Optional<std::string>& raw_device_id) {
+  if (!raw_device_id.has_value())
+    return;
+
+  auto callback_on_ui_thread = base::BindOnce(
+      [](MediaSessionControllersManager* controllers_manager,
+         RenderFrameHost* render_frame_host, int delegate_id,
+         const std::string& raw_device_id) {
+        controllers_manager->OnAudioOutputSinkChanged(
+            MediaPlayerId(render_frame_host, delegate_id), raw_device_id);
+      },
+      session_controllers_manager(), render_frame_host, delegate_id,
+      raw_device_id.value());
+
+  content::GetUIThreadTaskRunner({})->PostTask(
+      FROM_HERE, std::move(callback_on_ui_thread));
 }
 
 void MediaWebContentsObserver::OnBufferUnderflow(

content/browser/media/media_web_contents_observer.h

@@ -12,6 +12,7 @@
 
 #include "base/containers/flat_map.h"
 #include "base/macros.h"
+#include "base/memory/weak_ptr.h"
 #include "base/optional.h"
 #include "build/build_config.h"
 #include "content/browser/media/media_power_experiment_manager.h"
@@ -151,6 +152,10 @@ class CONTENT_EXPORT MediaWebContentsObserver : public WebContentsObserver {
   void OnAudioOutputSinkChanged(RenderFrameHost* render_frame_host,
                                 int delegate_id,
                                 std::string hashed_device_id);
+  void OnAudioOutputDeviceIdTranslated(
+      RenderFrameHost* render_frame_host,
+      int delegate_id,
+      const base::Optional<std::string>& raw_device_id);
   void OnBufferUnderflow(RenderFrameHost* render_frame_host, int delegate_id);
 
   device::mojom::WakeLock* GetAudioWakeLock();
@@ -190,6 +195,7 @@ class CONTENT_EXPORT MediaWebContentsObserver : public WebContentsObserver {
            std::unique_ptr<base::WeakPtrFactory<MediaWebContentsObserver>>>
       per_frame_factory_;
 
+  base::WeakPtrFactory<MediaWebContentsObserver> weak_ptr_factory_{this};
   DISALLOW_COPY_AND_ASSIGN(MediaWebContentsObserver);
 };