Add the ability to return descedant event listeners.

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/inspector/ThreadDebugger.h"
 
 #include "bindings/core/v8/ScriptCallStack.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8DOMException.h"
@@ skipping 280 matching lines @@
 void ThreadDebugger::getEventListenersCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     if (info.Length() < 1)
         return;
 
     ThreadDebugger* debugger = static_cast<ThreadDebugger*>(v8::Local<v8::External>::Cast(info.Data())->Value());
     DCHECK(debugger);
     v8::Isolate* isolate = info.GetIsolate();
     v8::Local<v8::Context> context = isolate->GetCurrentContext();
 
+    EventListenerFilter filterMask = static_cast<EventListenerFilter>(EventListenerFilter::ShowPassive | EventListenerFilter::ShowBlocking);
+    if (info.Length() > 1 && info[1]->IsObject()) {
+        v8::Local<v8::Object> options = v8::Local<v8::Object>::Cast(info[1]);
+
+        v8::Local<v8::Value> setting;
+        if (options->Get(context, v8String(isolate, "descendants")).ToLocal(&setting) && setting->IsTrue())
+            filterMask = static_cast<EventListenerFilter>(filterMask | EventListenerFilter::ShowDescendants);
+
+        if (options->Get(context, v8String(isolate, "passive")).ToLocal(&setting) && !setting->IsUndefined()) {
+            if (setting->IsFalse())
+                filterMask = static_cast<EventListenerFilter>(filterMask & ~EventListenerFilter::ShowPassive);
+            else
+                filterMask = static_cast<EventListenerFilter>(filterMask & ~EventListenerFilter::ShowBlocking);
+        }
+    }
+
     V8EventListenerInfoList listenerInfo;
     // eventListeners call can produce message on ErrorEvent during lazy event listener compilation.
     debugger->muteWarningsAndDeprecations();
-    InspectorDOMDebuggerAgent::eventListenersInfoForTarget(isolate, info[0], listenerInfo);
+    InspectorDOMDebuggerAgent::eventListenersInfoForTarget(isolate, info[0], filterMask, listenerInfo);
     debugger->unmuteWarningsAndDeprecations();
 
     v8::Local<v8::Object> result = v8::Object::New(isolate);
 
     v8::Local<v8::Function> removeFunc = v8::Function::New(isolate, removeEventListenerCallback, info[0]);
     v8::Local<v8::Function> toStringFunction;
     if (v8::Function::New(context, returnDataCallback, v8String(isolate, "function remove() { [Command Line API] }")).ToLocal(&toStringFunction))
         removeFunc->Set(v8String(context->GetIsolate(), "toString"), toStringFunction);
 
     AtomicString currentEventType;
     v8::Local<v8::Array> listeners;
     size_t outputIndex = 0;
     for (auto& info : listenerInfo) {
+        // Skip contexts not associated with the current context.
+        if (info.handler->CreationContext() != context)

[caseq, 2016/05/31 21:36:49]

I think this is the right places for this check to be, but my understanding is
that Pavel's suggestion was to use some security-origin based check (e.g.
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...).
Unlike simple checking for context, this should allow access to same-origin
subframes, though we also need to assure these will work well for
extension-based listeners (which we don't want to expose).

+            continue;
         if (currentEventType != info.eventType) {
             currentEventType = info.eventType;
-            listeners = v8::Array::New(isolate);
-            outputIndex = 0;
-            result->Set(v8String(isolate, currentEventType), listeners);
+            v8::Local<v8::Value> matchingList;
+            if (result->Get(context, v8String(isolate, currentEventType)).ToLocal(&matchingList) && matchingList->IsArray()) {
+                listeners = v8::Local<v8::Array>::Cast(matchingList);
+                outputIndex = listeners->Length();
+            } else {
+                listeners = v8::Array::New(isolate);
+                outputIndex = 0;
+                result->Set(v8String(isolate, currentEventType), listeners);
+            }
         }
 
         v8::Local<v8::Object> listenerObject = v8::Object::New(isolate);
         listenerObject->Set(v8String(isolate, "listener"), info.handler);
         listenerObject->Set(v8String(isolate, "useCapture"), v8::Boolean::New(isolate, info.useCapture));
         listenerObject->Set(v8String(isolate, "passive"), v8::Boolean::New(isolate, info.passive));
         listenerObject->Set(v8String(isolate, "type"), v8String(isolate, currentEventType));
         listenerObject->Set(v8String(isolate, "remove"), removeFunc);
         listeners->Set(outputIndex++, listenerObject);
     }
@@ skipping 57 matching lines @@
 {
     for (size_t index = 0; index < m_timers.size(); ++index) {
         if (m_timers[index] == timer) {
             m_timerCallbacks[index](m_timerData[index]);
             return;
         }
     }
 }
 
 } // namespace blink