Disable TtsApiTest.EngineError browser test on most OS-es (due to flakiness).

chrome/browser/speech/extension_api/tts_extension_apitest.cc

 // Copyright (c) 2012 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 <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/macros.h"
@@ skipping 393 matching lines @@
     EXPECT_CALL(mock_platform_impl_, Speak(_, "native speech 3", _, _, _))
       .WillOnce(DoAll(
           Invoke(&mock_platform_impl_,
                  &MockTtsPlatformImpl::SendEndEvent),
           Return(true)));
   }
 
   ASSERT_TRUE(RunExtensionTest("tts_engine/register_engine")) << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(TtsApiTest, EngineError) {
+// https://crbug.com/709115 tracks test flakiness.
+#if defined(OS_POSIX)
+#define MAYBE_EngineError DISABLED_EngineError
+#else
+#define MAYBE_EngineError EngineError
+#endif
+IN_PROC_BROWSER_TEST_F(TtsApiTest, MAYBE_EngineError) {
   EXPECT_CALL(mock_platform_impl_, IsSpeaking());
   EXPECT_CALL(mock_platform_impl_, StopSpeaking())
       .WillRepeatedly(Return(true));
 
   ASSERT_TRUE(RunExtensionTest("tts_engine/engine_error")) << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(TtsApiTest, EngineWordCallbacks) {
   EXPECT_CALL(mock_platform_impl_, IsSpeaking());
   EXPECT_CALL(mock_platform_impl_, StopSpeaking())
@@ skipping 28 matching lines @@
   // Test should fail when offline.
   ASSERT_FALSE(RunExtensionTest("tts_engine/network_speech_engine"));
 }
 
 // http://crbug.com/122474
 IN_PROC_BROWSER_TEST_F(TtsApiTest, EngineApi) {
   ASSERT_TRUE(RunExtensionTest("tts_engine/engine_api")) << message_;
 }
 
 }  // namespace extensions