Fix copy_rect calculation in CopyCurrentRendererPassToBitmap().

The calculation was second-guessing the copy request's subrect by force-translating its origin.  This manifested as bug 280724, where the compositing layer for Flash fullscreen was being read back with erroneous -64 by -64 translation.

Digging deeper, the RenderPass was drawing to output_rect=(-64, -64, screen_width+64, screen_height+64).  The client was requesting area=(0, 0, screen_width, screen_height), and this is actually the correct region within the output_rect for the fullscreen content.

Testing:

1. Ran cc_unittests --gtest_filter='*Readback*'
2. Installed Chromecast extension, and mirrored both normal tab content and fullscreen Flash content to Chromecast device.

BUG=280724

Review URL: https://chromiumcodereview.appspot.com/23967012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223722 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 5 deletions

diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index 241968e..394d79a 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -492,11 +492,8 @@ void SoftwareRenderer::CopyCurrentRenderPassToBitmap(
     DrawingFrame* frame,
     scoped_ptr<CopyOutputRequest> request) {
   gfx::Rect copy_rect = frame->current_render_pass->output_rect;
-  if (request->has_area()) {
-    // Intersect with the request's area, positioned with its origin at the
-    // origin of the full copy_rect.
-    copy_rect.Intersect(request->area() - copy_rect.OffsetFromOrigin());
-  }
+  if (request->has_area())
+    copy_rect.Intersect(request->area());
   gfx::Rect window_copy_rect = MoveFromDrawToWindowSpace(copy_rect);
 
   scoped_ptr<SkBitmap> bitmap(new SkBitmap);