Migrate AudioFocusChangeListener to browser and always send GAIN

content/browser/media/android/audio_focus_manager.cc

Index: content/browser/media/android/audio_focus_manager.cc
diff --git a/content/browser/media/android/audio_focus_manager.cc b/content/browser/media/android/audio_focus_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a258791f6043cf89f934bf4f3d0c4e102e663ecd
--- /dev/null
+++ b/content/browser/media/android/audio_focus_manager.cc
@@ -0,0 +1,70 @@
+// 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.
+
+#include "content/browser/media/android/audio_focus_manager.h"
+
+#include "base/android/jni_android.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/bind.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "content/browser/media/android/browser_media_player_manager.h"
+
+#include "jni/AudioFocusManager_jni.h"
+
+using base::android::AttachCurrentThread;
+using base::android::CheckException;
+using base::android::ScopedJavaLocalRef;
+
+namespace content {
+
+AudioFocusManager::AudioFocusManager(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
+    base::WeakPtr<BrowserMediaPlayerManager> manager)
+    : task_runner_(task_runner),
+      manager_(manager) {
+  DCHECK(task_runner_.get());
+  DCHECK(manager_);
+  j_audio_focus_manager_.Reset(
+      Java_AudioFocusManager_getInstance(
+          AttachCurrentThread(),
+          base::android::GetApplicationContext()));
+}
+
+AudioFocusManager::~AudioFocusManager() {}
+
+// static
+bool AudioFocusManager::RegisterAudioFocusManager(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+void AudioFocusManager::RequestAudioFocus(int player_id) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+  if (!j_audio_focus_manager_.is_null()) {
+    Java_AudioFocusManager_requestAudioFocus(
+        env, j_audio_focus_manager_.obj(),
+        reinterpret_cast<intptr_t>(this),
+        player_id);
+  }
+}
+
+void AudioFocusManager::AbandonAudioFocus(int player_id) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+  if (!j_audio_focus_manager_.is_null()) {
+    Java_AudioFocusManager_abandonAudioFocus(
+        env, j_audio_focus_manager_.obj(),
+        reinterpret_cast<intptr_t>(this),
+        player_id);
+  }
+}
+
+void AudioFocusManager::OnMediaInterrupted(JNIEnv*, jobject, jint player_id) {
+  if (manager_.get()) {
+    task_runner_->PostTask(FROM_HERE, base::Bind(
+        &BrowserMediaPlayerManager::OnMediaInterrupted, manager_, player_id));
+  }
+}
+
+}  // namespace content