Disable rendering on up-scale.

remoting/base/decoder_vp8.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/base/decoder_vp8.h"
 
 #include <math.h>
 
 #include "base/logging.h"
 #include "media/base/media.h"
@@ skipping 103 matching lines @@
   }
 }
 
 void DecoderVp8::RenderFrame(const SkISize& view_size,
                              const SkIRect& clip_area,
                              uint8* image_buffer,
                              int image_stride,
                              SkRegion* output_region) {
   SkIRect source_clip = SkIRect::MakeWH(last_image_->d_w, last_image_->d_h);
 
+  // ScaleYUVToRGB32WithRect doesn't support up-scaling, and our web-app never
+  // intentionally up-scales, so if we see up-scaling (e.g. during host resize
+  // or if the user applies page zoom) just don't render anything.
+  // TODO(wez): Remove this hack when ScaleYUVToRGB32WithRect can up-scale.
+  if (source_clip.width() < view_size.width() ||
+      source_clip.height() < view_size.height()) {
+    return;
+  }
+
   for (SkRegion::Iterator i(updated_region_); !i.done(); i.next()) {
     // Determine the scaled area affected by this rectangle changing.
     SkIRect rect = i.rect();
     if (!rect.intersect(source_clip))
       continue;
     rect = ScaleRect(rect, screen_size_, view_size);
     if (!rect.intersect(clip_area))
       continue;
 
     ConvertAndScaleYUVToRGB32Rect(last_image_->planes[0],
@@ skipping 10 matching lines @@
                                   rect);
 
     output_region->op(rect, SkRegion::kUnion_Op);
   }
 
   updated_region_.op(ScaleRect(clip_area, view_size, screen_size_),
                      SkRegion::kDifference_Op);
 }
 
 }  // namespace remoting