cc: Allow overlay candidates with transforms.

After https://codereview.chromium.org/2789363004 landed, Ozone Drm
supports the KMS "rotation" property that can be used to set a transform
to HW overlays.

This CL relaxes the transform restrictions of the fullscreen and
single on top overlay strategies.

Additionally, it makes sure that any configuration containing a transform
will be reject if the legacy page flip is being used.

After this CL WebGL and Pepper content can be promoted to HW overlay when
backed by a Gpu Memory Buffer.

BUG=b/36752417
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2794343003
Cr-Commit-Position: refs/heads/master@{#467697}

cc/output/overlay_strategy_fullscreen.cc

@@ -47,10 +47,6 @@ bool OverlayStrategyFullscreen::Attempt(
     return false;
   }
 
-  if (candidate.transform != gfx::OVERLAY_TRANSFORM_NONE) {
-    return false;
-  }
-
   if (!candidate.display_rect.origin().IsOrigin() ||
       gfx::ToRoundedSize(candidate.display_rect.size()) !=
           render_pass->output_rect.size() ||

cc/output/overlay_strategy_single_on_top.cc

@@ -37,8 +37,6 @@ bool OverlayStrategySingleOnTop::Attempt(
   for (auto it = quad_list->begin(); it != quad_list->end(); ++it) {
     OverlayCandidate candidate;
     if (OverlayCandidate::FromDrawQuad(resource_provider, *it, &candidate) &&
-        // TODO(dcastagna): Remove this once drm platform supports transforms.
-        candidate.transform == gfx::OVERLAY_TRANSFORM_NONE &&
         !OverlayCandidate::IsOccluded(candidate, quad_list->cbegin(), it)) {
       // We currently reject quads with alpha that do not request alpha blending
       // since the alpha channel might not be set to 1 and we're not disabling

cc/output/overlay_unittest.cc

@@ -1006,14 +1006,14 @@ TEST_F(SingleOverlayOnTopTest, AllowPositiveScaleTransform) {
   EXPECT_EQ(1U, candidate_list.size());
 }
 
-TEST_F(SingleOverlayOnTopTest, RejectTransform) {
+TEST_F(SingleOverlayOnTopTest, AcceptMirrorYTransform) {
   gfx::Rect rect = kOverlayRect;
   rect.Offset(0, -rect.height());
   std::unique_ptr<RenderPass> pass = CreateRenderPass();
   CreateCandidateQuadAt(resource_provider_.get(),
                         pass->shared_quad_state_list.back(), pass.get(), rect);
-  pass->shared_quad_state_list.back()
-      ->quad_to_target_transform.RotateAboutZAxis(90.f);
+  pass->shared_quad_state_list.back()->quad_to_target_transform.Scale(1.f,
+                                                                      -1.f);
 
   OverlayCandidateList candidate_list;
   base::flat_map<int, FilterOperations*> render_pass_filters;
@@ -1022,7 +1022,7 @@ TEST_F(SingleOverlayOnTopTest, RejectTransform) {
       resource_provider_.get(), pass.get(), render_pass_filters,
       render_pass_background_filters, &candidate_list, nullptr, nullptr,
       &damage_rect_, &content_bounds_);
-  ASSERT_EQ(0U, candidate_list.size());
+  ASSERT_EQ(1U, candidate_list.size());
 }
 
 TEST_F(UnderlayTest, Allow90DegreeRotation) {

ui/ozone/common/gpu/ozone_gpu_message_params.h

@@ -64,7 +64,7 @@ struct OverlayCheck_Params {
   bool operator<(const OverlayCheck_Params& plane) const;
 
   gfx::Size buffer_size;
-  gfx::OverlayTransform transform = gfx::OVERLAY_TRANSFORM_INVALID;
+  gfx::OverlayTransform transform = gfx::OVERLAY_TRANSFORM_NONE;
   gfx::BufferFormat format = gfx::BufferFormat::BGRA_8888;
   gfx::Rect display_rect;
   gfx::RectF crop_rect;
@@ -76,4 +76,3 @@ struct OverlayCheck_Params {
 }  // namespace ui
 
 #endif  // UI_OZONE_COMMON_GPU_OZONE_GPU_MESSAGE_PARAMS_H_
-

ui/ozone/platform/drm/gpu/hardware_display_plane_manager_legacy.cc

@@ -105,6 +105,9 @@ bool HardwareDisplayPlaneManagerLegacy::SetPlaneData(
     uint32_t crtc_id,
     const gfx::Rect& src_rect,
     CrtcController* crtc) {
+  // Legacy modesetting rejects transforms.
+  if (overlay.plane_transform != gfx::OVERLAY_TRANSFORM_NONE)
+    return false;
   if ((hw_plane->type() == HardwareDisplayPlane::kDummy) ||
       plane_list->legacy_page_flips.empty() ||
       plane_list->legacy_page_flips.back().crtc_id != crtc_id) {

ui/ozone/platform/drm/gpu/overlay_plane.cc

@@ -12,7 +12,7 @@ namespace ui {
 
 OverlayPlane::OverlayPlane(const scoped_refptr<ScanoutBuffer>& buffer)
     : buffer(buffer),
-      plane_transform(gfx::OVERLAY_TRANSFORM_INVALID),
+      plane_transform(gfx::OVERLAY_TRANSFORM_NONE),
       display_bounds(gfx::Point(), buffer->GetSize()),
       crop_rect(0, 0, 1, 1) {}