ozone: gbm: Add overlay support

ui/ozone/platform/dri/dri_wrapper.cc

Index: ui/ozone/platform/dri/dri_wrapper.cc
diff --git a/ui/ozone/platform/dri/dri_wrapper.cc b/ui/ozone/platform/dri/dri_wrapper.cc
index 3c2688cc5521e16c9caab122a5839d7efcd9a340..908ddf079f86080c74c10d22fe8f617dae861a12 100644
--- a/ui/ozone/platform/dri/dri_wrapper.cc
+++ b/ui/ozone/platform/dri/dri_wrapper.cc
@@ -12,6 +12,12 @@
 #include "base/logging.h"
 
 namespace ui {
+namespace {
+uint32_t ToFixedPoint(double v) {
+  // This returns a number in a 16-bit.16-bit fixed point.
+  return v * 65536.0;
+}
+}  // namespace
 
 DriWrapper::DriWrapper(const char* device_path) {
   fd_ = open(device_path, O_RDWR | O_CLOEXEC);
@@ -86,6 +92,27 @@ bool DriWrapper::PageFlip(uint32_t crtc_id,
                           data);
 }
 
+bool DriWrapper::PageFlipOverlay(uint32_t crtc_id,
+                                 uint32_t framebuffer,
+                                 const gfx::Rect& location,
+                                 const gfx::RectF& source,
+                                 int overlay_plane) {
+  CHECK(fd_ >= 0);
+  return !drmModeSetPlane(fd_,
+                          overlay_plane,
+                          crtc_id,
+                          framebuffer,
+                          0,
+                          location.x(),
+                          location.y(),
+                          location.width(),
+                          location.height(),
+                          ToFixedPoint(source.x()),
+                          ToFixedPoint(source.y()),
+                          ToFixedPoint(source.width()),
+                          ToFixedPoint(source.height()));
+}
+
 ScopedDrmFramebufferPtr DriWrapper::GetFramebuffer(uint32_t framebuffer) {
   CHECK(fd_ >= 0);
   return ScopedDrmFramebufferPtr(drmModeGetFB(fd_, framebuffer));