Fix DevTools support of worklets

third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp

Index: third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp
diff --git a/third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp b/third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp
index c5231f3773fa64d14dffbbc95a5f4dbf01dd43f0..05d803851d1c021b6fd28ca0fdf396bc3dbd61a7 100644
--- a/third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp
+++ b/third_party/WebKit/Source/core/inspector/MainThreadDebugger.cpp
@@ -193,8 +193,15 @@ bool MainThreadDebugger::callingContextCanAccessContext(v8::Local<v8::Context> c
     ASSERT(executionContext);
 
     if (executionContext->isMainThreadWorkletGlobalScope()) {

[dgozman, 2016/06/27 23:12:33]

I think this code is too complicated now, and should be moved to BindingSecurity
instead. Maybe the whole method taking two contexts can live there? It's
bindings after all. Let's ask owners.

[Yuki, 2016/06/28 04:38:53]

Yes, please move this code into BindingSecurity.  BindingSecurity should be
responsible about the origin check, and we want it to be one-stop.

[Gleb Lanbin, 2016/06/28 17:58:33]

Done.

+        ExecutionContext* callingExecutionContext = toExecutionContext(calling);
+        DCHECK(callingExecutionContext);
+        DOMWindow* callingDomWindow = toDOMWindow(calling);
+        if (callingExecutionContext->isMainThreadWorkletGlobalScope()) {

[dgozman, 2016/06/27 23:13:38]

This looks pretty good. However, adding the reverse check would be even better.

[Gleb Lanbin, 2016/06/28 17:58:33]

Done.

+            Frame* callingFrame = toMainThreadWorkletGlobalScope(callingExecutionContext)->frame();
+            callingDomWindow = callingFrame ? callingFrame->domWindow() : nullptr;
+        }
         MainThreadWorkletGlobalScope* globalScope = toMainThreadWorkletGlobalScope(executionContext);
-        return globalScope && BindingSecurity::shouldAllowAccessTo(m_isolate, toLocalDOMWindow(toDOMWindow(calling)), globalScope, DoNotReportSecurityError);
+        return globalScope && callingDomWindow && BindingSecurity::shouldAllowAccessTo(m_isolate, toLocalDOMWindow(callingDomWindow), globalScope, DoNotReportSecurityError);
     }
 
     DOMWindow* window = toDOMWindow(target);