Demote method EncodedImage::capacity() to private.

Bug: webrtc:9378
Change-Id: I83be267334fc778aff4eb2ad128d3ed693f755ff
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/185007
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32177}
diff --git a/modules/video_coding/frame_buffer.cc b/modules/video_coding/frame_buffer.cc
index 755acb2..d30170a 100644
--- a/modules/video_coding/frame_buffer.cc
+++ b/modules/video_coding/frame_buffer.cc
@@ -98,15 +98,16 @@
     }
   }
 
+  size_t oldSize = encoded_image_buffer_ ? encoded_image_buffer_->size() : 0;
   uint32_t requiredSizeBytes =
       size() + packet.sizeBytes +
       (packet.insertStartCode ? kH264StartCodeLengthBytes : 0);
-  if (requiredSizeBytes > capacity()) {
+  if (requiredSizeBytes > oldSize) {
     const uint8_t* prevBuffer = data();
     const uint32_t increments =
         requiredSizeBytes / kBufferIncStepSizeBytes +
         (requiredSizeBytes % kBufferIncStepSizeBytes > 0);
-    const uint32_t newSize = capacity() + increments * kBufferIncStepSizeBytes;
+    const uint32_t newSize = oldSize + increments * kBufferIncStepSizeBytes;
     if (newSize > kMaxJBFrameSizeBytes) {
       RTC_LOG(LS_ERROR) << "Failed to insert packet due to frame being too "
                            "big.";