Revert of Overlays: Remove special casing of primary overlay plane

cc/output/overlay_strategy_common.cc

Index: cc/output/overlay_strategy_common.cc
diff --git a/cc/output/overlay_strategy_common.cc b/cc/output/overlay_strategy_common.cc
index 36728dd9baf7ba48ba51dcb671f055d35ea612f2..5048b1a1c074b8e92a07bfc72ef4c65334d47c87 100644
--- a/cc/output/overlay_strategy_common.cc
+++ b/cc/output/overlay_strategy_common.cc
@@ -33,6 +33,12 @@
     return false;
   RenderPass* root_render_pass = render_passes_in_draw_order->back();
   DCHECK(root_render_pass);
+
+  // Add our primary surface.
+  OverlayCandidate main_image;
+  main_image.display_rect = gfx::RectF(root_render_pass->output_rect);
+  DCHECK(candidate_list->empty());
+  candidate_list->push_back(main_image);
 
   bool created_overlay = false;
   QuadList& quad_list = root_render_pass->quad_list;
@@ -56,6 +62,11 @@
         created_overlay = true;
         break;
     }
+  }
+
+  if (!created_overlay) {
+    DCHECK_EQ(1u, candidate_list->size());
+    candidate_list->clear();
   }
 
   return created_overlay;