Don't defer commit until draw if not drawing soon

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index 1a444c9a158168283165a077085333c7b510b15e..81376a96b017f01cb65da6e93d3735e6d1d07f4c 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -463,9 +463,20 @@ bool SchedulerStateMachine::ShouldCommit() const {
     return false;
   }
 
-  // Prioritize drawing the previous commit before finishing the next commit.
-  if (active_tree_needs_first_draw_)
-    return false;
+  if (settings_.impl_side_painting) {
+    // Prioritize drawing the previous commit before finishing the next commit.
+    bool active_tree_first_draw_is_imminent =
+        active_tree_needs_first_draw_ &&
+        begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_IDLE &&
+        pending_swaps_ < max_pending_swaps_;
+    if (active_tree_first_draw_is_imminent)
+      return false;
+  } else {
+    // If we only have an active tree, it is incorrect to replace it
+    // before we've drawn it.
+    if (active_tree_needs_first_draw_)
+      return false;
+  }
 
   return true;
 }