[Ozone] Fix SingleOnTop issue by checking if the quad is clipped.

cc/output/overlay_candidate.cc

 // Copyright 2014 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/output/overlay_candidate.h"
 
 #include <algorithm>
 #include <limits>
 #include "base/logging.h"
 #include "cc/base/math_util.h"
@@ skipping 20 matching lines @@
   else
     return NONE;
 }
 
 }  // namespace
 
 OverlayCandidate::OverlayCandidate()
     : transform(gfx::OVERLAY_TRANSFORM_NONE),
       format(RGBA_8888),
       uv_rect(0.f, 0.f, 1.f, 1.f),
+      is_clipped(false),
       use_output_surface_for_resource(false),
       resource_id(0),
       plane_z_order(0),
       overlay_handled(false) {}
 
 OverlayCandidate::~OverlayCandidate() {}
 
 // static
 gfx::OverlayTransform OverlayCandidate::GetOverlayTransform(
     const gfx::Transform& quad_transform,
@@ skipping 128 matching lines @@
     const gfx::Transform& quad_transform,
     const gfx::Rect& rect) {
   DCHECK(quad_transform.Preserves2dAxisAlignment());
 
   gfx::RectF float_rect(rect);
   quad_transform.TransformRect(&float_rect);
   return float_rect;
 }
 
 }  // namespace cc