Add EncodedImageCallback::OnEncodedImage().

OnEncodedImage() is going to replace Encoded(), which is deprecated now.
The new OnEncodedImage() returns Result struct that contains frame_id,
which tells the encoder RTP timestamp for the frame.

BUG=chromium:621691
R=niklas.enbom@webrtc.org, sprang@webrtc.org, stefan@webrtc.org

Review URL: https://codereview.webrtc.org/2089773002 .

Committed: https://crrev.com/ad34dbe934d47f88011045671b4aea00dbd5a795
Cr-Original-Commit-Position: refs/heads/master@{#13613}
Cr-Commit-Position: refs/heads/master@{#13615}
diff --git a/webrtc/modules/video_coding/video_coding_impl.cc b/webrtc/modules/video_coding/video_coding_impl.cc
index 077f336..2f709b6 100644
--- a/webrtc/modules/video_coding/video_coding_impl.cc
+++ b/webrtc/modules/video_coding/video_coding_impl.cc
@@ -45,7 +45,8 @@
 class EncodedImageCallbackWrapper : public EncodedImageCallback {
  public:
   EncodedImageCallbackWrapper()
-      : cs_(CriticalSectionWrapper::CreateCriticalSection()), callback_(NULL) {}
+      : cs_(CriticalSectionWrapper::CreateCriticalSection()),
+        callback_(nullptr) {}
 
   virtual ~EncodedImageCallbackWrapper() {}
 
@@ -54,14 +55,15 @@
     callback_ = callback;
   }
 
-  virtual int32_t Encoded(const EncodedImage& encoded_image,
-                          const CodecSpecificInfo* codec_specific_info,
-                          const RTPFragmentationHeader* fragmentation) {
+  virtual Result OnEncodedImage(const EncodedImage& encoded_image,
+                                const CodecSpecificInfo* codec_specific_info,
+                                const RTPFragmentationHeader* fragmentation) {
     CriticalSectionScoped cs(cs_.get());
-    if (callback_)
-      return callback_->Encoded(encoded_image, codec_specific_info,
-                                fragmentation);
-    return 0;
+    if (callback_) {
+      return callback_->OnEncodedImage(encoded_image, codec_specific_info,
+                                       fragmentation);
+    }
+    return Result(Result::ERROR_SEND_FAILED);
   }
 
  private: