Fix assert in GetOverlayRect when transforming video with Ozone overlay

One of my testcases for updating Chromecast to use Ozone overlays has
css animation on a video element's transform.  I hit an assert in the
call to ToNearestRect, which assumes the coordinates of the rectangle
are close to integers (within 0.01).

BUG=

Review URL: https://codereview.chromium.org/1110813002

Cr-Commit-Position: refs/heads/master@{#328218}

4 files changed, 14 insertions, 12 deletions

diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index ba3e07d..b13f4b2 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -3433,9 +3433,7 @@ void GLRenderer::ScheduleOverlays(DrawingFrame* frame) {
 
   ResourceProvider::ResourceIdArray resources;
   OverlayCandidateList& overlays = frame->overlay_list;
-  OverlayCandidateList::iterator it;
-  for (it = overlays.begin(); it != overlays.end(); ++it) {
-    const OverlayCandidate& overlay = *it;
+  for (const OverlayCandidate& overlay : overlays) {
     // Skip primary plane.
     if (overlay.plane_z_order == 0)
       continue;
@@ -3448,7 +3446,7 @@ void GLRenderer::ScheduleOverlays(DrawingFrame* frame) {
         overlay.plane_z_order,
         overlay.transform,
         pending_overlay_resources_.back()->texture_id(),
-        overlay.display_rect,
+        ToNearestRect(overlay.display_rect),
         overlay.uv_rect);
   }
 }
diff --git a/cc/output/overlay_candidate.cc b/cc/output/overlay_candidate.cc
index 46c3a7d..0cbd3de 100644
--- a/cc/output/overlay_candidate.cc
+++ b/cc/output/overlay_candidate.cc
@@ -128,13 +128,14 @@ gfx::OverlayTransform OverlayCandidate::ModifyTransform(
 }
 
 // static
-gfx::Rect OverlayCandidate::GetOverlayRect(const gfx::Transform& quad_transform,
-                                           const gfx::Rect& rect) {
+gfx::RectF OverlayCandidate::GetOverlayRect(
+    const gfx::Transform& quad_transform,
+    const gfx::Rect& rect) {
   DCHECK(quad_transform.IsPositiveScaleOrTranslation());
 
   gfx::RectF float_rect(rect);
   quad_transform.TransformRect(&float_rect);
-  return gfx::ToNearestRect(float_rect);
+  return float_rect;
 }
 
 }  // namespace cc
diff --git a/cc/output/overlay_candidate.h b/cc/output/overlay_candidate.h
index 28ae8cb..c6bb22a 100644
--- a/cc/output/overlay_candidate.h
+++ b/cc/output/overlay_candidate.h
@@ -24,8 +24,8 @@ class CC_EXPORT OverlayCandidate {
   // or OVERLAY_TRANSFORM_INVALID.
   static gfx::OverlayTransform ModifyTransform(gfx::OverlayTransform in,
                                                gfx::OverlayTransform delta);
-  static gfx::Rect GetOverlayRect(const gfx::Transform& quad_transform,
-                                  const gfx::Rect& rect);
+  static gfx::RectF GetOverlayRect(const gfx::Transform& quad_transform,
+                                   const gfx::Rect& rect);
 
   OverlayCandidate();
   ~OverlayCandidate();
@@ -34,8 +34,9 @@ class CC_EXPORT OverlayCandidate {
   gfx::OverlayTransform transform;
   // Format of the buffer to composite.
   ResourceFormat format;
-  // Rect on the display to position the overlay to.
-  gfx::Rect display_rect;
+  // Rect on the display to position the overlay to. Implementer must convert
+  // to integer coordinates if setting |overlay_handled| to true.
+  gfx::RectF display_rect;
   // Crop within the buffer to be placed inside |display_rect|.
   gfx::RectF uv_rect;
   // Texture resource to present in an overlay.
diff --git a/cc/output/overlay_candidate_validator.h b/cc/output/overlay_candidate_validator.h
index 036eafc..6064731 100644
--- a/cc/output/overlay_candidate_validator.h
+++ b/cc/output/overlay_candidate_validator.h
@@ -19,7 +19,9 @@ class CC_EXPORT OverlayCandidateValidator {
   // A list of possible overlay candidates is presented to this function.
   // The expected result is that those candidates that can be in a separate
   // plane are marked with |overlay_handled| set to true, otherwise they are
-  // to be traditionally composited.
+  // to be traditionally composited. Candidates with |overlay_handled| set to
+  // true must also have their |display_rect| converted to integer
+  // coordinates if necessary.
   virtual void CheckOverlaySupport(OverlayCandidateList* surfaces) = 0;
 
   virtual ~OverlayCandidateValidator() {}