TODO cleanup: Remove unused buffer_size

Remove unused variable buffer_size and rename bytes_in_buffer to
buffer_size in webm_read_frame.

Change-Id: I18b6ccbb044cd366610a5e39d83883cc0b174051
diff --git a/test/webm_video_source.h b/test/webm_video_source.h
index 650bc52..8258756 100644
--- a/test/webm_video_source.h
+++ b/test/webm_video_source.h
@@ -62,7 +62,7 @@
 
   void FillFrame() {
     ASSERT_TRUE(vpx_ctx_->file != NULL);
-    const int status = webm_read_frame(webm_ctx_, &buf_, &buf_sz_, &buf_sz_);
+    const int status = webm_read_frame(webm_ctx_, &buf_, &buf_sz_);
     ASSERT_GE(status, 0) << "webm_read_frame failed";
     if (status == 1) {
       end_of_file_ = true;
@@ -72,7 +72,7 @@
   void SeekToNextKeyFrame() {
     ASSERT_TRUE(vpx_ctx_->file != NULL);
     do {
-      const int status = webm_read_frame(webm_ctx_, &buf_, &buf_sz_, &buf_sz_);
+      const int status = webm_read_frame(webm_ctx_, &buf_, &buf_sz_);
       ASSERT_GE(status, 0) << "webm_read_frame failed";
       ++frame_;
       if (status == 1) {