android webview: allow cc to fail hardware draw

cc/scheduler/scheduler_state_machine.h

Index: cc/scheduler/scheduler_state_machine.h
diff --git a/cc/scheduler/scheduler_state_machine.h b/cc/scheduler/scheduler_state_machine.h
index c188941b832f599aedd2d900b880ec2ae6a1778e..e6a7222e1a368e7dcf0230e022aa9de5c22a7d6b 100644
--- a/cc/scheduler/scheduler_state_machine.h
+++ b/cc/scheduler/scheduler_state_machine.h
@@ -219,6 +219,9 @@ class CC_EXPORT SchedulerStateMachine {
   // Indicates production should be skipped to recover latency.
   void SetSkipNextBeginMainFrameToReduceLatency();
 
+  // Resourceless software draws are allowed even when invisible.
+  void SetResourcelessSoftareDraw(bool resourceless_draw);
+
   // Indicates whether drawing would, at this time, make sense.
   // CanDraw can be used to suppress flashes or checkerboarding
   // when such behavior would be undesirable.
@@ -319,6 +322,7 @@ class CC_EXPORT SchedulerStateMachine {
   bool needs_prepare_tiles_;
   bool needs_begin_main_frame_;
   bool visible_;
+  bool resourceless_draw_;
   bool can_draw_;
   bool has_pending_tree_;
   bool pending_tree_is_ready_for_activation_;