Add the ability to return descedant event listeners.

third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp

Index: third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp
diff --git a/third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp b/third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp
index e40898d35bbe65cc61e3951e85c8b4925071bfab..8d80b0cfc6bfda670f9d92ac65156d37a9ff3e5e 100644
--- a/third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp
+++ b/third_party/WebKit/Source/platform/v8_inspector/V8InjectedScriptHost.cpp
@@ -175,11 +175,21 @@ void V8InjectedScriptHost::getEventListenersCallback(const v8::FunctionCallbackI
     if (info.Length() < 1)
         return;
 
+    unsigned filterMask = V8EventListenerInfo::EventListenerFilterShowPassive | V8EventListenerInfo::EventListenerFilterShowBlocking;
+    if (info.Length() > 1 && info[1]->IsTrue())
+        filterMask |= V8EventListenerInfo::EventListenerFilterShowDescendants;
+
+    if (info.Length() > 2 && info[2]->IsFalse())
+        filterMask &= ~V8EventListenerInfo::EventListenerFilterShowPassive;
+
+    if (info.Length() > 3 && info[3]->IsFalse())
+        filterMask &= ~V8EventListenerInfo::EventListenerFilterShowBlocking;
+
     V8DebuggerClient* client = unwrapDebugger(info)->client();
     V8EventListenerInfoList listenerInfo;
     // eventListeners call can produce message on ErrorEvent during lazy event listener compilation.
     client->muteWarningsAndDeprecations();
-    client->eventListeners(info[0], listenerInfo);
+    client->eventListeners(info[0], filterMask, listenerInfo);
     client->unmuteWarningsAndDeprecations();
 
     v8::Local<v8::Object> result = v8::Object::New(info.GetIsolate());