Handle repeated and overlapping (re)starts of mock speechrecognizer.

components/test_runner/mock_web_speech_recognizer.cc

 // Copyright 2014 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 "components/test_runner/mock_web_speech_recognizer.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 165 matching lines @@
     blink::WebSpeechRecognizerClient* client) {
   handle_ = handle;
   client_ = client;
 }
 
 void MockWebSpeechRecognizer::start(
     const blink::WebSpeechRecognitionHandle& handle,
     const blink::WebSpeechRecognitionParams& params,
     blink::WebSpeechRecognizerClient* client) {
   was_aborted_ = false;
-  if (!client_) {
+  if (!client_ && !HasPendingNewContextTasks()) {
     handle_ = handle;
     client_ = client;
   } else {
     task_queue_.push_back(new SwitchClientHandleTask(this, handle, client));
   }
 
   task_queue_.push_back(
       new ClientCallTask(this, &blink::WebSpeechRecognizerClient::didStart));
   task_queue_.push_back(new ClientCallTask(
       this, &blink::WebSpeechRecognizerClient::didStartAudio));
@@ skipping 114 matching lines @@
   delete task;
 
   if (task_queue_.empty()) {
     task_queue_running_ = false;
     return;
   }
 
   PostRunTaskFromQueue();
 }
 
+bool MockWebSpeechRecognizer::HasPendingNewContextTasks() const {
+  for (const auto& task : task_queue_) {
+    if (task->isNewContextTask())
+      return true;
+  }
+  return false;
+}
+
 }  // namespace test_runner