Revert of Add EncodedImageCallback::OnEncodedImage(). (patchset #13 id:280001 of https://codereview.webrtc.org/2089773002/ )

Reason for revert:
broke internal tests

Original issue's description:
> 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
>
> Committed: https://crrev.com/ad34dbe934d47f88011045671b4aea00dbd5a795
> Cr-Commit-Position: refs/heads/master@{#13613}

TBR=pbos@webrtc.org,mflodman@webrtc.org,sprang@webrtc.org,stefan@webrtc.org,niklas.enbom@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:621691

Review-Url: https://codereview.webrtc.org/2206743002
Cr-Commit-Position: refs/heads/master@{#13614}
diff --git a/webrtc/modules/video_coding/video_coding_impl.cc b/webrtc/modules/video_coding/video_coding_impl.cc
index 2f709b6..077f336 100644
--- a/webrtc/modules/video_coding/video_coding_impl.cc
+++ b/webrtc/modules/video_coding/video_coding_impl.cc
@@ -45,8 +45,7 @@
 class EncodedImageCallbackWrapper : public EncodedImageCallback {
  public:
   EncodedImageCallbackWrapper()
-      : cs_(CriticalSectionWrapper::CreateCriticalSection()),
-        callback_(nullptr) {}
+      : cs_(CriticalSectionWrapper::CreateCriticalSection()), callback_(NULL) {}
 
   virtual ~EncodedImageCallbackWrapper() {}
 
@@ -55,15 +54,14 @@
     callback_ = callback;
   }
 
-  virtual Result OnEncodedImage(const EncodedImage& encoded_image,
-                                const CodecSpecificInfo* codec_specific_info,
-                                const RTPFragmentationHeader* fragmentation) {
+  virtual int32_t Encoded(const EncodedImage& encoded_image,
+                          const CodecSpecificInfo* codec_specific_info,
+                          const RTPFragmentationHeader* fragmentation) {
     CriticalSectionScoped cs(cs_.get());
-    if (callback_) {
-      return callback_->OnEncodedImage(encoded_image, codec_specific_info,
-                                       fragmentation);
-    }
-    return Result(Result::ERROR_SEND_FAILED);
+    if (callback_)
+      return callback_->Encoded(encoded_image, codec_specific_info,
+                                fragmentation);
+    return 0;
   }
 
  private: