Calling slow video renderer in case opacity is not 1.0.

BUG=41057
TEST=load page http://ddstreet.org/chrome-video-opacity-bug/ and see that the video is translucent.

Review URL: http://codereview.chromium.org/2848034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@51560 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 19 insertions, 0 deletions

diff --git a/webkit/glue/media/video_renderer_impl.cc b/webkit/glue/media/video_renderer_impl.cc
index d1a4fdc..1ba51f2 100644
--- a/webkit/glue/media/video_renderer_impl.cc
+++ b/webkit/glue/media/video_renderer_impl.cc
@@ -95,6 +95,24 @@ void VideoRendererImpl::Paint(skia::PlatformCanvas* canvas,
 // Disable the flipping and mirroring checks once we have it.
 bool VideoRendererImpl::CanFastPaint(skia::PlatformCanvas* canvas,
                                      const gfx::Rect& dest_rect) {
+  // Fast paint does not handle opacity value other than 1.0. Hence use slow
+  // paint if opacity is not 1.0. Since alpha = opacity * 0xFF, we check that
+  // alpha != 0xFF.
+  //
+  // Additonal notes: If opacity = 0.0, the chrome dispaly engine does not try
+  // to render the video. So, this method is never called. However, if the
+  // opacity = 0.0001, alpha is again 0, but the display engine tries to render
+  // the video. If we use Fast paint, the video shows up with opacity = 1.0.
+  // Hence we use slow paint also in the case where alpha = 0. It would be ideal
+  // if rendering was never called even for cases where alpha is 0. Created
+  // bug 48090 for this.
+  SkCanvas::LayerIter layer_iter(canvas, true);
+  SkColor sk_color = layer_iter.paint().getColor();
+  SkAlpha sk_alpha = SkColorGetA(sk_color);
+  if (sk_alpha != 0xFF) {
+    return false;
+  }
+
   const SkMatrix& total_matrix = canvas->getTotalMatrix();
   // Perform the following checks here:
   // 1. Check for skewing factors of the transformation matrix. They should be
@@ -124,6 +142,7 @@ bool VideoRendererImpl::CanFastPaint(skia::PlatformCanvas* canvas,
       return true;
     }
   }
+
   return false;
 }