Let Flash join and be controlled by media session

content/browser/media/session/pepper_player_delegate.cc

+// Copyright 2016 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 "content/browser/media/session/pepper_player_delegate.h"
+
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/media/session/pepper_playback_observer.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/common/frame_messages.h"
+
+namespace content {
+
+namespace {
+const double kDuckVolume = 0.2f;
+}  // anonymous namespace
+
+PepperPlayerDelegate::PepperPlayerDelegate(
+    WebContentsImpl* contents, int32_t pp_instance)
+    : contents_(contents),
+      pp_instance_(pp_instance) {}
+
+PepperPlayerDelegate::~PepperPlayerDelegate() = default;
+
+void PepperPlayerDelegate::OnSuspend(int player_id) {
+  DCHECK_EQ(player_id, 0);
+  SetVolume(player_id, kDuckVolume);
+}
+
+void PepperPlayerDelegate::OnResume(int player_id) {
+  DCHECK_EQ(player_id, 0);
+  SetVolume(player_id, 1.0f);
+}
+
+void PepperPlayerDelegate::OnSetVolumeMultiplier(int player_id,
+                                                 double volume_multiplier) {
+  DCHECK_EQ(player_id, 0);
+  SetVolume(player_id, volume_multiplier);
+}
+
+void PepperPlayerDelegate::SetVolume(int player_id, double volume) {
+  contents_->Send(new FrameMsg_SetPepperVolume(
+      contents_->GetMainFrame()->routing_id(), pp_instance_, volume));
+}
+
+}  // namespace content