[Blink] Modify SuspendableScriptExecutor to take a v8::Function

extensions/renderer/script_context.cc

Index: extensions/renderer/script_context.cc
diff --git a/extensions/renderer/script_context.cc b/extensions/renderer/script_context.cc
index f611ddebf7112e9d6fb6b63aa5d993fb77fc4c07..01e0b297f751faf4df171bd2c918421b12b8962d 100644
--- a/extensions/renderer/script_context.cc
+++ b/extensions/renderer/script_context.cc
@@ -202,6 +202,22 @@ v8::Local<v8::Value> ScriptContext::CallFunction(
           function, global, argc, argv)));
 }
 
+void ScriptContext::SafeCallFunction(const v8::Local<v8::Function>& function,
+                                     int argc,
+                                     v8::Local<v8::Value> argv[]) {
+  v8::HandleScope handle_scope(isolate());
+  v8::Context::Scope scope(v8_context());
+  v8::MicrotasksScope microtasks(isolate(),
+                                 v8::MicrotasksScope::kDoNotRunMicrotasks);
+  v8::Local<v8::Object> global = v8_context()->Global();
+  if (web_frame_) {
+    web_frame_->requestExecuteV8Function(function, global, argc, argv, nullptr);
+  } else {
+    // TODO(devlin): This probably isn't safe.

[dcheng, 2016/10/04 05:58:49]

Hmm, is it possible to attach devtools to a service worker? I'm just trying to
think of the normal ways we would get script re-entrancy. If devtools is
attached, how do we suspend script execution in the SW?

[Devlin, 2016/10/04 19:40:05]

That sounds like a question for falken. :)  Regardless, we'd definitely need
something different, since SWs don't have associated frames.

[falken, 2016/10/05 00:19:55]

Yes, you can attach DevTools to service workers and set breakpoints etc.
+dgozman.

[dgozman, 2016/10/05 01:25:42]

This should be fine as long as you execute JS via SuspendableScriptExecutor,
which is an ActiveDOMObject. We pause all of these while on breakpoint.

+    function->Call(global, argc, argv);
+  }
+}
+
 v8::Local<v8::Value> ScriptContext::CallFunction(
     const v8::Local<v8::Function>& function) const {
   DCHECK(thread_checker_.CalledOnValidThread());