Store SourceLocation in ErrorEvent.

third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp

Index: third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
diff --git a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
index 85d180321a5ec3e1503bf450df83abdbd2b8655b..7a2741d6899d03fb537b56effeb0d68e300ea847 100644
--- a/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
+++ b/third_party/WebKit/Source/core/workers/InProcessWorkerMessagingProxy.cpp
@@ -170,7 +170,7 @@ void InProcessWorkerMessagingProxy::reportException(const String& errorMessage,
     // because terminated workers no longer deliver messages (section 4.6 of the
     // WebWorker spec), but they do report exceptions.
 
-    ErrorEvent* event = ErrorEvent::create(errorMessage, location->url(), location->lineNumber(), location->columnNumber(), nullptr);
+    ErrorEvent* event = ErrorEvent::create(errorMessage, location->clone(), nullptr);

[sof, 2016/05/27 09:34:55]

Doesn't the clone() have to make an isolated copy of the m_url string here? The
string stems from another thread.

cf.
https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Win10/105...

[sof, 2016/05/29 06:16:16]

As this CL introduces half a dozen crashers, please address

(
https://storage.googleapis.com/chromium-layout-test-archives/win_chromium_rel...
)

     if (m_workerObject->dispatchEvent(event) == DispatchEventResult::NotCanceled)
         postTaskToWorkerGlobalScope(createCrossThreadTask(&processUnhandledExceptionOnWorkerGlobalScope, errorMessage, passed(std::move(location))));
 }