VideoLayerImpl: subtract 1 from visible size when calculating tex stretch.

cc/layers/video_layer_impl.cc

 // Copyright 2011 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 "cc/layers/video_layer_impl.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 168 matching lines @@
       draw_properties()
           .occlusion_in_content_space.GetOcclusionWithGivenDrawTransform(
               transform);
   gfx::Rect visible_quad_rect =
       occlusion_in_video_space.GetUnoccludedContentRect(quad_rect);
   if (visible_quad_rect.IsEmpty())
     return;
 
   // Pixels for macroblocked formats.
   const float tex_width_scale =
-      static_cast<float>(visible_rect.width()) / coded_size.width();
+      static_cast<float>(visible_rect.width() - 1) / coded_size.width();

[Pawel Osciak, 2016/02/01 00:40:58]

I'm wondering if we should be checking for 0,0 (and perhaps 1,1) visible rect
before subtracting?

   const float tex_height_scale =
-      static_cast<float>(visible_rect.height()) / coded_size.height();
+      static_cast<float>(visible_rect.height() - 1) / coded_size.height();
 
   switch (frame_resource_type_) {
     // TODO(danakj): Remove this, hide it in the hardware path.
     case VideoFrameExternalResources::SOFTWARE_RESOURCE: {
       DCHECK_EQ(frame_resources_.size(), 0u);
       DCHECK_EQ(software_resources_.size(), 1u);
       if (software_resources_.size() < 1u)
         break;
       bool premultiplied_alpha = true;
       gfx::PointF uv_top_left(0.f, 0.f);
@@ skipping 197 matching lines @@
 void VideoLayerImpl::SetNeedsRedraw() {
   SetUpdateRect(gfx::UnionRects(update_rect(), gfx::Rect(bounds())));
   layer_tree_impl()->SetNeedsRedraw();
 }
 
 const char* VideoLayerImpl::LayerTypeAsString() const {
   return "cc::VideoLayerImpl";
 }
 
 }  // namespace cc