sync compositor: Set display viewport for software draw

cc/surfaces/display.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/surfaces/display.h"
 
 #include <stddef.h>
 
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 115 matching lines @@
 }
 
 void Display::SetColorSpace(const gfx::ColorSpace& color_space) {
   device_color_space_ = color_space;
 }
 
 void Display::SetExternalClip(const gfx::Rect& clip) {
   external_clip_ = clip;
 }
 
+void Display::SetExternalViewport(const gfx::Rect& viewport) {
+  external_viewport_ = viewport;
+}
+
 void Display::SetOutputIsSecure(bool secure) {
   if (secure == output_is_secure_)
     return;
   output_is_secure_ = secure;
 
   if (aggregator_) {
     aggregator_->set_output_is_secure(secure);
     // Force a redraw.
     if (!current_surface_id_.is_null())
       aggregator_->SetFullDamageForSurface(current_surface_id_);
@@ skipping 132 matching lines @@
 
   // If the surface is suspended then the resources to be used by the draw are
   // likely destroyed.
   if (output_surface_->SurfaceIsSuspendForRecycle()) {
     TRACE_EVENT_INSTANT0("cc", "Surface is suspended for recycle.",
                          TRACE_EVENT_SCOPE_THREAD);
     should_draw = false;
   }
 
   if (should_draw) {
-    gfx::Rect device_viewport_rect = gfx::Rect(current_surface_size_);
+    gfx::Rect device_viewport_rect = external_viewport_.IsEmpty()
+                                         ? gfx::Rect(current_surface_size_)
+                                         : external_viewport_;
     gfx::Rect device_clip_rect =
         external_clip_.IsEmpty() ? device_viewport_rect : external_clip_;
 
     bool disable_image_filtering =
         frame.metadata.is_resourceless_software_draw_with_scroll_or_animation;
     if (software_renderer_) {
       software_renderer_->SetDisablePictureQuadImageFiltering(
           disable_image_filtering);
     } else {
       // This should only be set for software draws in synchronous compositor.
@@ skipping 120 matching lines @@
 
   if (surface_id == current_surface_id_)
     UpdateRootSurfaceResourcesLocked();
 }
 
 const SurfaceId& Display::CurrentSurfaceId() {
   return current_surface_id_;
 }
 
 }  // namespace cc