Pause EME player whose external surface is stolen by another player

android_webview/native/external_video_surface_container_impl.cc

 // Copyright 2014 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 "android_webview/native/external_video_surface_container_impl.h"
 
 #include "base/android/jni_android.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "jni/ExternalVideoSurfaceContainer_jni.h"
 #include "ui/gfx/rect_f.h"
@@ skipping 25 matching lines @@
     const SurfaceCreatedCB& surface_created_cb,
     const SurfaceDestroyedCB& surface_destroyed_cb) {
   surface_created_cb_ = surface_created_cb;
   surface_destroyed_cb_ = surface_destroyed_cb;
 
   JNIEnv* env = AttachCurrentThread();
   Java_ExternalVideoSurfaceContainer_requestExternalVideoSurface(
       env, jobject_.obj(), static_cast<jint>(player_id));
 }
 
+int ExternalVideoSurfaceContainerImpl::GetCurrentPlayerId() {
+  JNIEnv* env = AttachCurrentThread();
+  jclass cls = env->GetObjectClass(jobject_.obj());
+  jfieldID fid = env->GetStaticFieldID(cls, "INVALID_PLAYER_ID", "I");
+  int invalid_player = static_cast<int>(env->GetStaticIntField(cls, fid));

[boliu, 2014/12/09 18:15:18]

We basically never write manual jni code in chromium. The java/native classes
are generally considered tightly coupled so assuming INVALID_PLAYER_ID = -1 in
native code is ok. (It's certainly better than assuming there's a static int
member variable called INVALID_PLAYER_ID)

But content/ and things outside of content/ have a strict API in content/public,
so should make them loosely coupled.

+
+  int current_player = static_cast<int>(
+      Java_ExternalVideoSurfaceContainer_getCurrentPlayerId(
+          env, jobject_.obj()));
+
+  if (current_player == invalid_player)

[boliu, 2014/12/09 18:15:18]

You can just do if (current_player < 0) here.

+    return kInvalidPlayerId;
+  else
+    return current_player;
+}
+
 void ExternalVideoSurfaceContainerImpl::ReleaseExternalVideoSurface(
     int player_id) {
   JNIEnv* env = AttachCurrentThread();
   Java_ExternalVideoSurfaceContainer_releaseExternalVideoSurface(
       env, jobject_.obj(), static_cast<jint>(player_id));
 
   surface_created_cb_.Reset();
   surface_destroyed_cb_.Reset();
 }
 
@@ skipping 26 matching lines @@
     JNIEnv* env, jobject obj, jint player_id) {
   if (!surface_destroyed_cb_.is_null())
     surface_destroyed_cb_.Run(static_cast<int>(player_id));
 }
 
 bool RegisterExternalVideoSurfaceContainer(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android_webview