Single overlay test selector

Selects one on top overlay, if possible, from a main plane + single overlay combination

BUG=370522

Review URL: https://codereview.chromium.org/489193002

Cr-Commit-Position: refs/heads/master@{#291627}

ui/ozone/platform/dri/gbm_surface_factory.cc

@@ -6,6 +6,7 @@
 
 #include <gbm.h>
 
+#include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "third_party/khronos/EGL/egl.h"
 #include "ui/ozone/platform/dri/gbm_buffer.h"
@@ -13,9 +14,54 @@
 #include "ui/ozone/platform/dri/gbm_surfaceless.h"
 #include "ui/ozone/platform/dri/screen_manager.h"
 #include "ui/ozone/public/native_pixmap.h"
+#include "ui/ozone/public/overlay_candidates_ozone.h"
+#include "ui/ozone/public/ozone_switches.h"
 #include "ui/ozone/public/surface_ozone_egl.h"
 
 namespace ui {
+namespace {
+
+class SingleOverlay : public OverlayCandidatesOzone {
+ public:
+  SingleOverlay() {}
+  virtual ~SingleOverlay() {}
+
+  virtual void CheckOverlaySupport(OverlaySurfaceCandidateList* candidates) {
+    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;
+      }
+      if (overlay->plane_z_order > 0 &&
+          IsTransformSupported(overlay->transform)) {
+        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
 
 GbmSurfaceFactory::GbmSurfaceFactory(bool allow_surfaceless)
     : DriSurfaceFactory(NULL, NULL),
@@ -125,6 +171,14 @@ scoped_refptr<ui::NativePixmap> GbmSurfaceFactory::CreateNativePixmap(
   return scoped_refptr<GbmPixmap>(new GbmPixmap(buffer));
 }
 
+OverlayCandidatesOzone* GbmSurfaceFactory::GetOverlayCandidates(
+    gfx::AcceleratedWidget w) {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kOzoneTestSingleOverlaySupport))
+    return new SingleOverlay();
+  return NULL;
+}
+
 bool GbmSurfaceFactory::ScheduleOverlayPlane(
     gfx::AcceleratedWidget widget,
     int plane_z_order,

ui/ozone/platform/dri/gbm_surface_factory.h

@@ -34,6 +34,8 @@ class GbmSurfaceFactory : public DriSurfaceFactory {
   virtual scoped_refptr<ui::NativePixmap> CreateNativePixmap(
       gfx::Size size,
       BufferFormat format) OVERRIDE;
+  virtual OverlayCandidatesOzone* GetOverlayCandidates(
+      gfx::AcceleratedWidget w) OVERRIDE;
   virtual bool ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                                     int plane_z_order,
                                     gfx::OverlayTransform plane_transform,

ui/ozone/public/ozone_switches.cc

@@ -16,4 +16,8 @@ const char kOzoneDumpFile[] = "ozone-dump-file";
 // mode there is no EGL surface.
 const char kOzoneUseSurfaceless[] = "ozone-use-surfaceless";
 
+// Enable support for a single overlay plane.
+const char kOzoneTestSingleOverlaySupport[] =
+    "ozone-test-single-overlay-support";
+
 }  // namespace switches

ui/ozone/public/ozone_switches.h

@@ -16,6 +16,8 @@ OZONE_EXPORT extern const char kOzoneDumpFile[];
 
 OZONE_EXPORT extern const char kOzoneUseSurfaceless[];
 
+OZONE_EXPORT extern const char kOzoneTestSingleOverlaySupport[];
+
 }  // namespace switches
 
 #endif  // UI_OZONE_PUBLIC_OZONE_SWITCHES_H_