Adding an api to get number of event listeners.

chrome/test/chromedriver/chrome/event_listener_count.cc

Index: chrome/test/chromedriver/chrome/event_listener_count.cc
diff --git a/chrome/test/chromedriver/chrome/event_listener_count.cc b/chrome/test/chromedriver/chrome/event_listener_count.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b25c3f170708e78baf017c3a89dec949f87f913f
--- /dev/null
+++ b/chrome/test/chromedriver/chrome/event_listener_count.cc
@@ -0,0 +1,66 @@
+// Copyright 2013 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 "chrome/test/chromedriver/chrome/event_listener_count.h"
+
+#include "base/json/json_reader.h"
+#include "base/logging.h"
+#include "base/values.h"
+#include "chrome/test/chromedriver/chrome/devtools_client.h"
+#include "chrome/test/chromedriver/chrome/status.h"
+
+
+EventListenerCount::EventListenerCount(DevToolsClient* client)
+    : client_(client) {
+  client_->AddListener(this);
+}
+
+EventListenerCount::~EventListenerCount() {}
+
+Status EventListenerCount::GetEventListenersCount(int *count) {
+  if (count == NULL)
+    return Status(kForbidden);
+
+  scoped_ptr<base::DictionaryValue>* result;
+  Status status1 = GetEventListenersCountInternal(result);
+  if (status1.IsError())
+      return status1;
+
+  bool isEventListenerValueSet = (*result)->GetIntegerWithoutPathExpansion(
+      "jsEventListeners", count);
+  if (!isEventListenerValueSet)
+    return Status(kUnknownError);
+
+  base::DictionaryValue params;
+  Status status2 = client_->SendCommand("Debugger.disable", params);
+  if (status2.IsError())
+      return status2;
+
+  return Status(kOk);
+}
+
+Status EventListenerCount::GetEventListenersCountInternal(
+    scoped_ptr<base::DictionaryValue>* result) {
+
+  base::DictionaryValue params;
+  const char* kMethods[] = {
+      "Debugger.enable",
+      "HeapProfiler.collectGarbage",
+      "Memory.getDOMCounters"

[chrisgao (Use stgao instead), 2013/10/26 00:54:01]

It seems no need to enable the debugger.

And I think we can move the code here to WebViewImpl::GetEventListenersCount you
added in web_view_impl.cc

+  };
+  for (size_t i = 0; i < arraysize(kMethods); ++i) {
+    Status status = client_->SendCommand(kMethods[i], params);
+    if (status.IsError())
+      return status;
+  }
+
+  base::DictionaryValue uid_params;
+  uid_params.SetInteger("uid", -1);
+  Status status = client_->SendCommandAndGetResult(
+      "Memory.getDOMCounters", uid_params, result);
+  if (status.IsError())
+    return status;
+  return Status(kOk);
+}
+