Move ExternalVideoSurfaceHolder from WebContents UserData to BrowserMediaPlayerManager.

android_webview/native/external_video_surface_container_impl.h

Index: android_webview/native/external_video_surface_container_impl.h
diff --git a/android_webview/native/external_video_surface_container_impl.h b/android_webview/native/external_video_surface_container_impl.h
index c5d9f0705bc85196ea407f2fcd5ec708eb2c2b86..4d34f83e44bb3f27b67b4702fbbb13cfde2d5756 100644
--- a/android_webview/native/external_video_surface_container_impl.h
+++ b/android_webview/native/external_video_surface_container_impl.h
@@ -11,13 +11,11 @@
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "content/public/browser/android/external_video_surface_container.h"
-#include "content/public/browser/web_contents_user_data.h"
 
 namespace android_webview {
 
 class ExternalVideoSurfaceContainerImpl
-    : public content::ExternalVideoSurfaceContainer,
-      public content::WebContentsUserData<ExternalVideoSurfaceContainerImpl> {
+    : public content::ExternalVideoSurfaceContainer {
  public:
   typedef base::Callback<void(int, jobject)> SurfaceCreatedCB;
   typedef base::Callback<void(int)> SurfaceDestroyedCB;