Rename EncodedImage::_buffer --> buffer_, and make private

Bug: webrtc:9378
Change-Id: I0a0636077b270a7c73bafafb958132fa648aca70
Reviewed-on: https://webrtc-review.googlesource.com/c/117722
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26294}
diff --git a/modules/video_coding/frame_buffer.cc b/modules/video_coding/frame_buffer.cc
index 37709c9..70b2030 100644
--- a/modules/video_coding/frame_buffer.cc
+++ b/modules/video_coding/frame_buffer.cc
@@ -105,7 +105,7 @@
       (packet.insertStartCode ? kH264StartCodeLengthBytes : 0) +
       EncodedImage::GetBufferPaddingBytes(packet.codec);
   if (requiredSizeBytes >= capacity()) {
-    const uint8_t* prevBuffer = _buffer;
+    const uint8_t* prevBuffer = data();
     const uint32_t increments =
         requiredSizeBytes / kBufferIncStepSizeBytes +
         (requiredSizeBytes % kBufferIncStepSizeBytes > 0);
@@ -116,7 +116,7 @@
       return kSizeError;
     }
     VerifyAndAllocate(newSize);
-    _sessionInfo.UpdateDataPointers(prevBuffer, _buffer);
+    _sessionInfo.UpdateDataPointers(prevBuffer, data());
   }
 
   if (packet.width > 0 && packet.height > 0) {
@@ -128,7 +128,7 @@
   if (packet.sizeBytes > 0)
     CopyCodecSpecific(&packet.video_header);
 
-  int retVal = _sessionInfo.InsertPacket(packet, _buffer, frame_data);
+  int retVal = _sessionInfo.InsertPacket(packet, data(), frame_data);
   if (retVal == -1) {
     return kSizeError;
   } else if (retVal == -2) {