Resize output_rect of aggregated CompositorFrame to enable it to be drawn when resizing.

cc/surfaces/display.cc

Index: cc/surfaces/display.cc
diff --git a/cc/surfaces/display.cc b/cc/surfaces/display.cc
index 7cd9d6d126b566dd5547595523d92a181a2d466d..cc1b34130b4caf189744f7549127cf29b0b5661b 100644
--- a/cc/surfaces/display.cc
+++ b/cc/surfaces/display.cc
@@ -218,14 +218,22 @@ bool Display::DrawAndSwap() {
   gfx::Size surface_size;
   bool have_damage = false;
   if (!frame_data->render_pass_list.empty()) {
-    surface_size = frame_data->render_pass_list.back()->output_rect.size();
-    have_damage =
-        !frame_data->render_pass_list.back()->damage_rect.size().IsEmpty();
+    RenderPass& last_render_pass = *frame_data->render_pass_list.back();
+    if (last_render_pass.output_rect.size() != current_surface_size_ &&
+        last_render_pass.damage_rect == last_render_pass.output_rect &&
+        !current_surface_size_.IsEmpty()) {
+      // Resize the output rect to the current surface size so that we won't
+      // skip the draw and so that the GL swap won't stretch the output.
+      last_render_pass.output_rect.set_size(current_surface_size_);
+      last_render_pass.damage_rect = last_render_pass.output_rect;
+    }
+    surface_size = last_render_pass.output_rect.size();
+    have_damage = !last_render_pass.damage_rect.size().IsEmpty();
   }
 
   bool size_matches = surface_size == current_surface_size_;
   if (!size_matches)
-    TRACE_EVENT_INSTANT0("cc", "Size missmatch.", TRACE_EVENT_SCOPE_THREAD);
+    TRACE_EVENT_INSTANT0("cc", "Size mismatch.", TRACE_EVENT_SCOPE_THREAD);

[brianderson, 2015/11/04 01:40:25]

In what cases would we hit this trace after this patch?

 
   bool should_draw = !frame->metadata.latency_info.empty() ||
                      have_copy_requests || (have_damage && size_matches);