ozone: Add overlay candidate implementation that queries support via IPC

ui/ozone/platform/drm/host/drm_overlay_manager.cc

Index: ui/ozone/platform/drm/host/drm_overlay_manager.cc
diff --git a/ui/ozone/platform/drm/host/drm_overlay_manager.cc b/ui/ozone/platform/drm/host/drm_overlay_manager.cc
index 747c43845d31ab0083102f67de5e0bc0f2f53cbe..3a6475efe86a260f9417abee8f4804009ef209c0 100644
--- a/ui/ozone/platform/drm/host/drm_overlay_manager.cc
+++ b/ui/ozone/platform/drm/host/drm_overlay_manager.cc
@@ -6,70 +6,30 @@
 
 #include "base/command_line.h"
 #include "ui/gfx/geometry/rect_conversions.h"
+#include "ui/ozone/platform/drm/host/drm_overlay_candidates_host.h"
 #include "ui/ozone/public/overlay_candidates_ozone.h"
 #include "ui/ozone/public/ozone_switches.h"
 
 namespace ui {
-namespace {
 
-class SingleOverlay : public OverlayCandidatesOzone {
- public:
-  SingleOverlay() {}
-  ~SingleOverlay() override {}
-
-  void CheckOverlaySupport(OverlaySurfaceCandidateList* candidates) override {
-    if (candidates->size() == 2) {
-      OverlayCandidatesOzone::OverlaySurfaceCandidate* first =
-          &(*candidates)[0];
-      OverlayCandidatesOzone::OverlaySurfaceCandidate* second =
-          &(*candidates)[1];
-      OverlayCandidatesOzone::OverlaySurfaceCandidate* overlay;
-      if (first->plane_z_order == 0) {
-        overlay = second;
-      } else if (second->plane_z_order == 0) {
-        overlay = first;
-      } else {
-        NOTREACHED();
-        return;
-      }
-      // 0.01 constant chosen to match DCHECKs in gfx::ToNearestRect and avoid
-      // that code asserting on quads that we accept.
-      if (overlay->plane_z_order > 0 &&
-          IsTransformSupported(overlay->transform) &&
-          gfx::IsNearestRectWithinDistance(overlay->display_rect, 0.01f)) {
-        overlay->overlay_handled = true;
-      }
-    }
-  }
-
- private:
-  bool IsTransformSupported(gfx::OverlayTransform transform) {
-    switch (transform) {
-      case gfx::OVERLAY_TRANSFORM_NONE:
-        return true;
-      default:
-        return false;
-    }
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(SingleOverlay);
-};
-
-}  // namespace
-
-DrmOverlayManager::DrmOverlayManager(bool allow_surfaceless)
-    : allow_surfaceless_(allow_surfaceless) {
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kOzoneTestSingleOverlaySupport))
-    candidates_ = make_scoped_ptr(new SingleOverlay());
+DrmOverlayManager::DrmOverlayManager(
+    bool allow_surfaceless,
+    DrmGpuPlatformSupportHost* platform_support_host)
+    : platform_support_host_(platform_support_host),
+      allow_surfaceless_(allow_surfaceless) {
+  is_supported_ = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kOzoneTestSingleOverlaySupport);
 }
 
 DrmOverlayManager::~DrmOverlayManager() {
 }
 
-OverlayCandidatesOzone* DrmOverlayManager::GetOverlayCandidates(
+scoped_ptr<OverlayCandidatesOzone> DrmOverlayManager::GetOverlayCandidates(
     gfx::AcceleratedWidget w) {
-  return candidates_.get();
+  if (!is_supported_)
+    return nullptr;
+  return scoped_ptr<OverlayCandidatesOzone>(
+      new DrmOverlayCandidatesHost(w, platform_support_host_));
 }
 
 bool DrmOverlayManager::CanShowPrimaryPlaneAsOverlay() {