cc: Partial draw without partial swap support.

cc/output/gl_renderer.cc

 // Copyright 2010 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/output/gl_renderer.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 2429 matching lines @@
   }
 }
 
 void GLRenderer::FinishDrawingFrame() {
   if (use_sync_query_) {
     DCHECK(current_sync_query_);
     current_sync_query_->End();
     pending_sync_queries_.push_back(std::move(current_sync_query_));
   }
 
-  swap_buffer_rect_.Union(current_frame()->root_damage_rect);
+  damage_rect_.Union(current_frame()->root_damage_rect);
   if (overdraw_feedback_)
-    FlushOverdrawFeedback(swap_buffer_rect_);
+    FlushOverdrawFeedback(damage_rect_);
 
   if (use_swap_with_bounds_)
     swap_content_bounds_ = current_frame()->root_content_bounds;
 
   current_framebuffer_lock_ = nullptr;
 
   gl_->Disable(GL_BLEND);
   blend_shadow_ = false;
 
   ScheduleCALayers();
@@ skipping 147 matching lines @@
   DCHECK(visible_);
 
   TRACE_EVENT0("cc", "GLRenderer::SwapBuffers");
   // We're done! Time to swapbuffers!
 
   gfx::Size surface_size = surface_size_for_swap_buffers();
 
   OutputSurfaceFrame output_frame;
   output_frame.latency_info = std::move(latency_info);
   output_frame.size = surface_size;
+  output_frame.damage_rect = damage_rect_;
   if (use_swap_with_bounds_) {
     output_frame.content_bounds = std::move(swap_content_bounds_);
   } else if (use_partial_swap_) {
     // If supported, we can save significant bandwidth by only swapping the
     // damaged/scissored region (clamped to the viewport).
-    swap_buffer_rect_.Intersect(gfx::Rect(surface_size));
+    gfx::Rect swap_buffer_rect = damage_rect_;
+    swap_buffer_rect.Intersect(gfx::Rect(surface_size));
     int flipped_y_pos_of_rect_bottom = surface_size.height() -
-                                       swap_buffer_rect_.y() -
-                                       swap_buffer_rect_.height();
+                                       swap_buffer_rect.y() -
+                                       swap_buffer_rect.height();
     output_frame.sub_buffer_rect =
-        gfx::Rect(swap_buffer_rect_.x(),
+        gfx::Rect(swap_buffer_rect.x(),
                   FlippedRootFramebuffer() ? flipped_y_pos_of_rect_bottom
-                                           : swap_buffer_rect_.y(),
-                  swap_buffer_rect_.width(), swap_buffer_rect_.height());
-  } else if (swap_buffer_rect_.IsEmpty() && allow_empty_swap_) {
-    output_frame.sub_buffer_rect = swap_buffer_rect_;
+                                           : swap_buffer_rect.y(),
+                  swap_buffer_rect.width(), swap_buffer_rect.height());
+  } else if (damage_rect_.IsEmpty() && allow_empty_swap_) {
+    output_frame.sub_buffer_rect = gfx::Rect();
   }
 
   swapping_overlay_resources_.push_back(std::move(pending_overlay_resources_));
   pending_overlay_resources_.clear();
 
   output_surface_->SwapBuffers(std::move(output_frame));
 
-  swap_buffer_rect_ = gfx::Rect();
+  damage_rect_ = gfx::Rect();
 }
 
 void GLRenderer::SwapBuffersComplete() {
   if (settings_->release_overlay_resources_after_gpu_query) {
     // Once a resource has been swap-ACKed, send a query to the GPU process to
     // ask if the resource is no longer being consumed by the system compositor.
     // The response will come with the next swap-ACK.
     if (!swapping_overlay_resources_.empty()) {
       for (OverlayResourceLock& lock : swapping_overlay_resources_.front()) {
         unsigned texture = lock->texture_id();
@@ skipping 942 matching lines @@
     return;
 
   // Report GPU overdraw as a percentage of |max_result|.
   TRACE_COUNTER1(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.overdraw"), "GPU Overdraw",
       (std::accumulate(overdraw->begin(), overdraw->end(), 0) * 100) /
           max_result);
 }
 
 }  // namespace cc