Move MediaDrmBridge provision communication to native side.

chrome/browser/android/chrome_media_client_android.h

Index: chrome/browser/android/chrome_media_client_android.h
diff --git a/chrome/browser/android/chrome_media_client_android.h b/chrome/browser/android/chrome_media_client_android.h
index d489e420c53883a275a0b1119239bcaf565304f3..1e8e12a638daf61d8c9f637d223936060759e3ae 100644
--- a/chrome/browser/android/chrome_media_client_android.h
+++ b/chrome/browser/android/chrome_media_client_android.h
@@ -14,6 +14,9 @@ class ChromeMediaClientAndroid : public media::MediaClientAndroid {
   ChromeMediaClientAndroid();
   ~ChromeMediaClientAndroid() override;
 
+  // media::MediaClientAndroid implementation:
+  scoped_ptr<media::ProvisionFetcher> CreateDefaultFetcher() const override;

[xhwang, 2015/11/06 23:08:18]

naming nit: CreateProvisionFetcher would be more explicit.

But here we'll always use the active user's profile, which could be easily
misused when handling requests from other profiles.

Since this is only used by MediaDrmCredentialManager, and
MediaDrmCredentialManager is only used by chrome/. Can we just move
MediaDrmCredentialManager to chrome/ to avoid exposing at all?

[Tima Vaisburd, 2015/11/11 03:03:33]

Done move.

+
  private:
   // media::MediaClientAndroid implementation:
   media::MediaDrmBridgeDelegate* GetMediaDrmBridgeDelegate(