Use IDCompositionSurface to implement DirectCompositionSurfaceWin.

content/browser/compositor/gpu_browser_compositor_output_surface.cc

Index: content/browser/compositor/gpu_browser_compositor_output_surface.cc
diff --git a/content/browser/compositor/gpu_browser_compositor_output_surface.cc b/content/browser/compositor/gpu_browser_compositor_output_surface.cc
index 8ad8384dbaf8e62208841f95deb10c877d651ceb..6ee9f63489f7844f91b1952db99d1c3f5827c484 100644
--- a/content/browser/compositor/gpu_browser_compositor_output_surface.cc
+++ b/content/browser/compositor/gpu_browser_compositor_output_surface.cc
@@ -88,6 +88,8 @@ void GpuBrowserCompositorOutputSurface::Reshape(
     const gfx::ColorSpace& color_space,
     bool has_alpha,
     bool use_stencil) {
+  size_ = size;
+  has_set_draw_rectangle_since_last_resize_ = false;
   context_provider()->ContextGL()->ResizeCHROMIUM(
       size.width(), size.height(), device_scale_factor, has_alpha);
 }
@@ -108,6 +110,8 @@ void GpuBrowserCompositorOutputSurface::SwapBuffers(
     }
   }
 
+  set_draw_rectangle_for_frame_ = false;
+
   if (swap_rect == gfx::Rect(frame.size))
     context_provider_->ContextSupport()->Swap();
   else
@@ -136,6 +140,19 @@ void GpuBrowserCompositorOutputSurface::SetSurfaceSuspendedForRecycle(
     bool suspended) {}
 #endif
 
+void GpuBrowserCompositorOutputSurface::SetDrawRectangle(
+    const gfx::Rect& rect) {
+  if (set_draw_rectangle_for_frame_)
+    return;
+  DCHECK(gfx::Rect(size_).Contains(rect));
+  DCHECK(has_set_draw_rectangle_since_last_resize_ ||

[dcheng, 2017/02/15 06:57:05]

Is it OK to DCHECK here? I wonder because
DirectCompositionSurfaceWin::SetDrawRectangle has something similar (but they
are actual if statements).

+         (gfx::Rect(size_) == rect));
+  set_draw_rectangle_for_frame_ = true;
+  has_set_draw_rectangle_since_last_resize_ = true;
+  context_provider()->ContextGL()->SetDrawRectangleCHROMIUM(
+      rect.x(), rect.y(), rect.width(), rect.height());
+}
+
 gpu::CommandBufferProxyImpl*
 GpuBrowserCompositorOutputSurface::GetCommandBufferProxy() {
   ui::ContextProviderCommandBuffer* provider_command_buffer =