Emit a console warning when blocking event listener is delayed for too long

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

Index: third_party/WebKit/Source/core/inspector/InspectorDOMDebuggerAgent.cpp
diff --git a/third_party/WebKit/Source/core/inspector/InspectorDOMDebuggerAgent.cpp b/third_party/WebKit/Source/core/inspector/InspectorDOMDebuggerAgent.cpp
index 743c452559ad8112d1288fccab97a26c37f742b3..328319a95f53cd52516f211d98a3c497736dd51e 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorDOMDebuggerAgent.cpp
+++ b/third_party/WebKit/Source/core/inspector/InspectorDOMDebuggerAgent.cpp
@@ -57,6 +57,14 @@ static const char instrumentationEventCategoryType[] = "instrumentation:";
 const uint32_t inheritableDOMBreakpointTypesMask = (1 << SubtreeModified);
 const int domBreakpointDerivedTypeShift = 16;
 
+void getFunctionLocation(v8::Local<v8::Function> function, String& scriptId, int& lineNumber, int& columnNumber)
+{
+    int scriptIdValue = function->ScriptId();
+    scriptId = String::number(scriptIdValue);
+    lineNumber = function->GetScriptLineNumber();
+    columnNumber = function->GetScriptColumnNumber();
+}
+
 } // namespace
 
 namespace blink {
@@ -111,6 +119,25 @@ void InspectorDOMDebuggerAgent::eventListenersInfoForTarget(v8::Isolate* isolate
     }
 }
 
+v8::Local<v8::Function> InspectorDOMDebuggerAgent::eventListenerEffectiveFunction(v8::Isolate* isolate, v8::Local<v8::Object> handler)
+{
+    v8::Local<v8::Function> function;
+    if (handler->IsFunction()) {
+        function = handler.As<v8::Function>();
+    } else if (handler->IsObject()) {
+        v8::Local<v8::Value> property;
+        // Try the "handleEvent" method (EventListener interface).
+        if (handler->Get(handler->CreationContext(), v8AtomicString(isolate, "handleEvent")).ToLocal(&property) && property->IsFunction())
+            function = property.As<v8::Function>();
+        // Fall back to the "constructor" property.
+        else if (handler->Get(handler->CreationContext(), v8AtomicString(isolate, "constructor")).ToLocal(&property) && property->IsFunction())
+            function = property.As<v8::Function>();
+    }
+    if (!function.IsEmpty())
+        return getBoundFunction(function);
+    return v8::Local<v8::Function>();
+}
+
 InspectorDOMDebuggerAgent::InspectorDOMDebuggerAgent(v8::Isolate* isolate, InspectorDOMAgent* domAgent, V8InspectorSession* v8Session)
     : InspectorBaseAgent<InspectorDOMDebuggerAgent, protocol::Frontend::DOMDebugger>("DOMDebugger")
     , m_isolate(isolate)