Split MediaSessionStateChanged() and MediaSessionMetadataChanged()

content/browser/android/web_contents_observer_proxy.h

 // 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.
 
 #ifndef CONTENT_BROWSER_ANDROID_WEB_CONTENTS_OBSERVER_PROXY_H_
 #define CONTENT_BROWSER_ANDROID_WEB_CONTENTS_OBSERVER_PROXY_H_
 
 #include <jni.h>
 
 #include "base/android/jni_weak_ref.h"
@@ skipping 54 matching lines @@
   void DocumentLoadedInFrame(RenderFrameHost* render_frame_host) override;
   void NavigationEntryCommitted(
       const LoadCommittedDetails& load_details) override;
   void WebContentsDestroyed() override;
   void DidAttachInterstitialPage() override;
   void DidDetachInterstitialPage() override;
   void DidChangeThemeColor(SkColor color) override;
   void DidStartNavigationToPendingEntry(
       const GURL& url,
       ReloadType reload_type) override;
-  void MediaSessionStateChanged(
-      bool is_controllable,
-      bool is_suspended,
+  void MediaSessionStateChanged(bool is_controllable,
+                                bool is_suspended) override;
+  void MediaSessionMetadataChanged(
       const base::Optional<MediaMetadata>& metadata) override;

[clamy, 2016/10/12 11:43:50]

Considering that this is an optional parameter, couldn't you already avoid to
send every time?

[Zhiqiang Zhang (Slow), 2016/10/12 12:08:27]

As I said in the other reply, `nullopt` metadata is used for unsetting. So if
the metadata is not null, it needs to be passed through this function. So this
where we want to improve.

[clamy, 2016/10/12 12:25:04]

Acknowledged.

[clamy, 2016/10/12 11:43:50]

Now that it moves to its own function, should metadata be made non optional?

[Zhiqiang Zhang (Slow), 2016/10/12 12:08:27]

Not in our case. `metadata` is passed from Blink, and in Blink we can use null
for unsetting metadata, so we want the "unset" signal be passed to the Java
side.

[clamy, 2016/10/12 12:25:04]

Acknowledged.

   void SetToBaseURLForDataURLIfNeeded(std::string* url);
 
   void DidFailLoadInternal(bool is_provisional_load,
                            bool is_main_frame,
                            int error_code,
                            const base::string16& description,
                            const GURL& url,
                            bool was_ignored_by_handler);
 
   base::android::ScopedJavaGlobalRef<jobject> java_observer_;
   GURL base_url_of_last_started_data_url_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserverProxy);
 };
 
 bool RegisterWebContentsObserverProxy(JNIEnv* env);
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_WEB_CONTENTS_OBSERVER_PROXY_H_