4 files changed, 58 insertions, 0 deletions

diff --git a/ui/ozone/platform/cast/surface_factory_cast.cc b/ui/ozone/platform/cast/surface_factory_cast.cc
index 9a0a466..3288f43 100644
--- a/ui/ozone/platform/cast/surface_factory_cast.cc
+++ b/ui/ozone/platform/cast/surface_factory_cast.cc
@@ -197,6 +197,10 @@ scoped_refptr<NativePixmap> SurfaceFactoryCast::CreateNativePixmap(
                               const gfx::RectF& crop_rect) override {
       return true;
     }
+    void SetScalingCallback(const ScalingCallback& scaling_callback) override {}
+    scoped_refptr<NativePixmap> GetScaledPixmap(gfx::Size new_size) override {
+      return nullptr;
+    }
 
    private:
     ~CastPixmap() override {}
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer.cc b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
index 8da5e5d..c92ba44 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer.cc
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer.cc
@@ -11,6 +11,7 @@
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
+#include "ui/gfx/geometry/size_conversions.h"
 #include "ui/ozone/platform/drm/gpu/drm_window.h"
 #include "ui/ozone/platform/drm/gpu/gbm_device.h"
 
@@ -83,6 +84,14 @@ bool GbmPixmap::Initialize() {
   return true;
 }
 
+void GbmPixmap::SetScalingCallback(const ScalingCallback& scaling_callback) {
+  scaling_callback_ = scaling_callback;
+}
+
+scoped_refptr<NativePixmap> GbmPixmap::GetScaledPixmap(gfx::Size new_size) {
+  return scaling_callback_.Run(new_size);
+}
+
 GbmPixmap::~GbmPixmap() {
   if (dma_buf_ > 0)
     close(dma_buf_);
@@ -105,9 +114,37 @@ bool GbmPixmap::ScheduleOverlayPlane(gfx::AcceleratedWidget widget,
                                      gfx::OverlayTransform plane_transform,
                                      const gfx::Rect& display_bounds,
                                      const gfx::RectF& crop_rect) {
+  gfx::Size required_size;
+  if (plane_z_order &&
+      ShouldApplyScaling(display_bounds, crop_rect, &required_size)) {
+    scoped_refptr<NativePixmap> scaled_pixmap = GetScaledPixmap(required_size);
+    if (scaled_pixmap) {
+      return scaled_pixmap->ScheduleOverlayPlane(
+          widget, plane_z_order, plane_transform, display_bounds, crop_rect);
+    } else {
+      return false;
+    }
+  }
+
   screen_manager_->GetWindow(widget)->QueueOverlayPlane(OverlayPlane(
       buffer_, plane_z_order, plane_transform, display_bounds, crop_rect));
   return true;
 }
 
+bool GbmPixmap::ShouldApplyScaling(const gfx::Rect& display_bounds,
+                                   const gfx::RectF& crop_rect,
+                                   gfx::Size* required_size) {
+  if (crop_rect.width() == 0 || crop_rect.height() == 0) {
+    PLOG(ERROR) << "ShouldApplyScaling passed zero scaling target.";
+    return false;
+  }
+
+  gfx::Size pixmap_size = buffer_->GetSize();
+  // If the required size is not integer-sized, round it to the next integer.
+  *required_size = gfx::ToCeiledSize(
+      gfx::SizeF(display_bounds.width() / crop_rect.width(),
+                 display_bounds.height() / crop_rect.height()));
+  return pixmap_size != *required_size;
+}
+
 }  // namespace ui
diff --git a/ui/ozone/platform/drm/gpu/gbm_buffer.h b/ui/ozone/platform/drm/gpu/gbm_buffer.h
index 3f0c5d7..4f420e7 100644
--- a/ui/ozone/platform/drm/gpu/gbm_buffer.h
+++ b/ui/ozone/platform/drm/gpu/gbm_buffer.h
@@ -39,6 +39,8 @@ class GbmPixmap : public NativePixmap {
   GbmPixmap(const scoped_refptr<GbmBuffer>& buffer,
             ScreenManager* screen_manager);
   bool Initialize();
+  void SetScalingCallback(const ScalingCallback& scaling_callback) override;
+  scoped_refptr<NativePixmap> GetScaledPixmap(gfx::Size new_size) override;
 
   // NativePixmap:
   void* GetEGLClientBuffer() override;
@@ -54,12 +56,17 @@ class GbmPixmap : public NativePixmap {
 
  private:
   ~GbmPixmap() override;
+  bool ShouldApplyScaling(const gfx::Rect& display_bounds,
+                          const gfx::RectF& crop_rect,
+                          gfx::Size* required_size);
 
   scoped_refptr<GbmBuffer> buffer_;
   int dma_buf_ = -1;
 
   ScreenManager* screen_manager_;  // Not owned.
 
+  ScalingCallback scaling_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(GbmPixmap);
 };
 
diff --git a/ui/ozone/public/native_pixmap.h b/ui/ozone/public/native_pixmap.h
index a1204f7..0251a12 100644
--- a/ui/ozone/public/native_pixmap.h
+++ b/ui/ozone/public/native_pixmap.h
@@ -5,6 +5,7 @@
 #ifndef UI_OZONE_PUBLIC_NATIVE_PIXMAP_H_
 #define UI_OZONE_PUBLIC_NATIVE_PIXMAP_H_
 
+#include "base/bind.h"
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/overlay_transform.h"
@@ -43,6 +44,15 @@ class NativePixmap : public base::RefCountedThreadSafe<NativePixmap> {
                                     const gfx::Rect& display_bounds,
                                     const gfx::RectF& crop_rect) = 0;
 
+  // This represents a callback function pointing to scaling unit like VPP
+  // to do scaling operations on native pixmap with required size.
+  typedef base::Callback<scoped_refptr<NativePixmap>(gfx::Size)>
+      ScalingCallback;
+
+  // Set callback function for the pixmap used for scaling.
+  virtual void SetScalingCallback(const ScalingCallback& scaling_callback) = 0;
+  virtual scoped_refptr<NativePixmap> GetScaledPixmap(gfx::Size new_size) = 0;
+
  protected:
   virtual ~NativePixmap() {}