cc: Unify use of DidSwapBuffers() and did_request_swap

cc/trees/thread_proxy.cc

Index: cc/trees/thread_proxy.cc
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index cac9bc6f94bceb2034e60448a4415b633a496dde..a7986d47bbe4e88f9f6da69ff854f09aca8a5efa 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -1231,25 +1231,25 @@ DrawSwapReadbackResult ThreadProxy::DrawSwapReadbackInternal(
   // Check for a pending CompositeAndReadback.
   if (drawing_for_readback) {
     DCHECK(!swap_requested);
-    result.did_readback = false;
+    bool did_readback = false;
     if (draw_frame) {
       if (!impl().layer_tree_host_impl->IsContextLost()) {
         impl().layer_tree_host_impl->Readback(impl().readback_request->pixels,
                                               impl().readback_request->rect);
-        result.did_readback = true;
+        did_readback = true;
       } else {
         result.draw_result = DrawSwapReadbackResult::DRAW_ABORTED_CONTEXT_LOST;
       }
     }
-    impl().readback_request->success = result.did_readback;
+    impl().readback_request->success = did_readback;
     impl().readback_request->completion.Signal();
     impl().readback_request = NULL;
   } else if (draw_frame) {
     DCHECK(swap_requested);
-    result.did_request_swap = impl().layer_tree_host_impl->SwapBuffers(frame);
+    bool did_request_swap = impl().layer_tree_host_impl->SwapBuffers(frame);
 
     // We don't know if we have incomplete tiles if we didn't actually swap.
-    if (result.did_request_swap) {
+    if (did_request_swap) {
       DCHECK(!frame.has_no_damage);
       SetSwapUsedIncompleteTileOnImplThread(frame.contains_incomplete_tile);
     }