Add TaskRunnerHelper::get for Frame that casts to LocalFrame if possible or uses nullptr.

third_party/WebKit/Source/core/dom/TaskRunnerHelper.h

Index: third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
diff --git a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
index 0ca15474dfc6083ea8782ceea86e02ed3b156a2e..f37cbbf7f16803edc8bbbac762a5bebed4bb033a 100644
--- a/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
+++ b/third_party/WebKit/Source/core/dom/TaskRunnerHelper.h
@@ -13,6 +13,7 @@ namespace blink {
 
 class Document;
 class ExecutionContext;
+class Frame;
 class LocalFrame;
 class ScriptState;
 class WebTaskRunner;
@@ -79,6 +80,7 @@ class CORE_EXPORT TaskRunnerHelper final {
 
  public:
   static RefPtr<WebTaskRunner> get(TaskType, LocalFrame*);
+  static RefPtr<WebTaskRunner> get(TaskType, Frame*);
   static RefPtr<WebTaskRunner> get(TaskType, Document*);
   static RefPtr<WebTaskRunner> get(TaskType, ExecutionContext*);
   static RefPtr<WebTaskRunner> get(TaskType, ScriptState*);