Move MutableDataY{,U,V} methods to I420Buffer only.

webrtc/api/android/jni/androidmediadecoder_jni.cc

Index: webrtc/api/android/jni/androidmediadecoder_jni.cc
diff --git a/webrtc/api/android/jni/androidmediadecoder_jni.cc b/webrtc/api/android/jni/androidmediadecoder_jni.cc
index 2a7e68976aff881386d4ab363cebf30311080782..c9c34d661188f9148d6fe03fefa08c412310c17c 100644
--- a/webrtc/api/android/jni/androidmediadecoder_jni.cc
+++ b/webrtc/api/android/jni/androidmediadecoder_jni.cc
@@ -782,7 +782,9 @@ bool MediaCodecVideoDecoder::DeliverPendingOutputs(
     payload += output_buffer_offset;
 
     // Create yuv420 frame.
-    frame_buffer = decoded_frame_pool_.CreateBuffer(width, height);
+    rtc::scoped_refptr<webrtc::I420Buffer> i420_buffer;
+
+    i420_buffer = decoded_frame_pool_.CreateBuffer(width, height);
     if (color_format == COLOR_FormatYUV420Planar) {
       RTC_CHECK_EQ(0, stride % 2);
       RTC_CHECK_EQ(0, slice_height % 2);
@@ -794,12 +796,9 @@ bool MediaCodecVideoDecoder::DeliverPendingOutputs(
       libyuv::I420Copy(y_ptr, stride,
                        u_ptr, uv_stride,
                        v_ptr, uv_stride,
-                       frame_buffer->MutableDataY(),
-                       frame_buffer->StrideY(),
-                       frame_buffer->MutableDataU(),
-                       frame_buffer->StrideU(),
-                       frame_buffer->MutableDataV(),
-                       frame_buffer->StrideV(),
+                       i420_buffer->MutableDataY(), i420_buffer->StrideY(),
+                       i420_buffer->MutableDataU(), i420_buffer->StrideU(),
+                       i420_buffer->MutableDataV(), i420_buffer->StrideV(),
                        width, height);
     } else {
       // All other supported formats are nv12.
@@ -808,14 +807,13 @@ bool MediaCodecVideoDecoder::DeliverPendingOutputs(
       libyuv::NV12ToI420(
           y_ptr, stride,
           uv_ptr, stride,
-          frame_buffer->MutableDataY(),
-          frame_buffer->StrideY(),
-          frame_buffer->MutableDataU(),
-          frame_buffer->StrideU(),
-          frame_buffer->MutableDataV(),
-          frame_buffer->StrideV(),
+          i420_buffer->MutableDataY(), i420_buffer->StrideY(),
+          i420_buffer->MutableDataU(), i420_buffer->StrideU(),
+          i420_buffer->MutableDataV(), i420_buffer->StrideV(),
           width, height);
     }
+    frame_buffer = i420_buffer;
+
     // Return output byte buffer back to codec.
     jni->CallVoidMethod(
         *j_media_codec_video_decoder_,