ozone: Remove primary plane optimization.

Chrome browser compositor sends the primary buffer as a
normal overlay, therefore the optimization to replace the
primary plane can be done earlier in the browser compositor (crrev.com/2281033003).

This CL removes the optimization in Ozone.

BUG=b/29430506

Review-Url: https://codereview.chromium.org/2284893002
Cr-Commit-Position: refs/heads/master@{#415169}

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

@@ -204,31 +204,6 @@ TEST_F(HardwareDisplayControllerTest, CheckOverlayTestMode) {
   EXPECT_EQ(2, drm_->get_overlay_flip_call_count());
 }
 
-TEST_F(HardwareDisplayControllerTest, CheckOverlayFullScreenMode) {
-  ui::OverlayPlane plane1(scoped_refptr<ui::ScanoutBuffer>(
-      new ui::MockScanoutBuffer(kDefaultModeSize)));
-  ui::OverlayPlane plane2(scoped_refptr<ui::ScanoutBuffer>(
-                              new ui::MockScanoutBuffer(kDefaultModeSize)),
-                          1, gfx::OVERLAY_TRANSFORM_NONE,
-                          gfx::Rect(kDefaultModeSize),
-                          gfx::RectF(kDefaultModeSizeF));
-
-  EXPECT_TRUE(controller_->Modeset(plane1, kDefaultMode));
-
-  std::vector<ui::OverlayPlane> planes;
-  planes.push_back(plane1);
-  planes.push_back(plane2);
-
-  controller_->SchedulePageFlip(
-      planes, base::Bind(&HardwareDisplayControllerTest::PageFlipCallback,
-                         base::Unretained(this)));
-  drm_->RunCallbacks();
-  EXPECT_EQ(gfx::SwapResult::SWAP_ACK, last_swap_result_);
-  EXPECT_EQ(1, page_flips_);
-  EXPECT_EQ(1, drm_->get_page_flip_call_count());
-  EXPECT_EQ(0, drm_->get_overlay_flip_call_count());
-}
-
 TEST_F(HardwareDisplayControllerTest, RejectUnderlays) {
   ui::OverlayPlane plane1(scoped_refptr<ui::ScanoutBuffer>(
       new ui::MockScanoutBuffer(kDefaultModeSize)));

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

@@ -232,8 +232,6 @@ bool HardwareDisplayPlaneManager::AssignOverlayPlanes(
   }
 
   size_t plane_idx = 0;
-  HardwareDisplayPlane* primary_plane = nullptr;
-  gfx::Rect primary_display_bounds;
   for (const auto& plane : overlay_list) {
     HardwareDisplayPlane* hw_plane =
         FindNextUnusedPlane(&plane_idx, crtc_index, plane);
@@ -244,7 +242,6 @@ bool HardwareDisplayPlaneManager::AssignOverlayPlanes(
     }
 
     gfx::Rect fixed_point_rect;
-    uint32_t fourcc_format = plane.buffer->GetFramebufferPixelFormat();
     if (hw_plane->type() != HardwareDisplayPlane::kDummy) {
       const gfx::Size& size = plane.buffer->GetSize();
       gfx::RectF crop_rect = plane.crop_rect;
@@ -260,32 +257,6 @@ bool HardwareDisplayPlaneManager::AssignOverlayPlanes(
                                    to_fixed_point(crop_rect.height()));
     }
 
-    // If Overlay completely covers primary and isn't transparent, than use
-    // it as primary. This reduces the no of planes which need to be read in
-    // display controller side.
-    if (primary_plane) {
-      // TODO(dcastagna): Check if we can move this optimization to
-      // GLRenderer::ScheduleOverlays.
-      // Note that Chromium compositor promotes buffers to overlays (ABGR
-      // ones too) only if blending is not needed.
-      // TODO(dcastagna): this should check if the format is the same as
-      // primary_plane->format minus alpha. Changing the format of the primary
-      // plane currently works on rockchip with 3.14 kernel and won't work with
-      // newer kernels. Remove this hack as soon as we can switch the primary
-      // plane format to match overlay buffers formats.
-      if ((fourcc_format == DRM_FORMAT_XBGR8888 ||
-           fourcc_format == DRM_FORMAT_ABGR8888 ||
-           fourcc_format == DRM_FORMAT_XRGB8888 ||
-           fourcc_format == DRM_FORMAT_ARGB8888) &&
-          primary_display_bounds == plane.display_bounds) {
-        ResetCurrentPlaneList(plane_list);
-        hw_plane = primary_plane;
-      }
-    } else {
-      primary_plane = hw_plane;
-      primary_display_bounds = plane.display_bounds;
-    }
-
     if (!SetPlaneData(plane_list, hw_plane, plane, crtc_id, fixed_point_rect,
                       crtc)) {
       ResetCurrentPlaneList(plane_list);