cc: Partial draw without partial swap support.

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

Index: content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
diff --git a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
index e0464b673542e0bb869c817602abb29885aa64ba..00214df7db472b0c39f4f77d35bdaf877512582f 100644
--- a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
+++ b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc
@@ -74,7 +74,7 @@ void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
   // happens, we'd see the wrong swap size there?
   swap_size_ = reshape_size_;
   buffer_queue_->SwapBuffers(frame.sub_buffer_rect ? *frame.sub_buffer_rect
-                                                   : gfx::Rect(swap_size_));
+                                                   : frame.damage_rect);
   GpuBrowserCompositorOutputSurface::SwapBuffers(std::move(frame));
 }
 
@@ -83,6 +83,11 @@ void GpuSurfacelessBrowserCompositorOutputSurface::BindFramebuffer() {
   buffer_queue_->BindFramebuffer();
 }
 
+bool GpuSurfacelessBrowserCompositorOutputSurface::CanPartialDraw(
+    const gfx::Rect& damage) {
+  return buffer_queue_->CanPartialDraw(damage);
+}
+
 GLenum GpuSurfacelessBrowserCompositorOutputSurface::
     GetFramebufferCopyTextureFormat() {
   return buffer_queue_->internal_format();