Add more unit tests for ImageResource's DecodeError

third_party/WebKit/Source/core/loader/resource/MockImageResourceObserver.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/loader/resource/MockImageResourceObserver.h"
 
 #include "core/loader/resource/ImageResource.h"
 #include "core/loader/resource/ImageResourceContent.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 26 matching lines @@
   m_imageWidthOnLastImageChanged =
       m_content->hasImage() ? m_content->getImage()->width() : 0;
 }
 
 void MockImageResourceObserver::imageNotifyFinished(
     ImageResourceContent* image) {
   ASSERT_EQ(0, m_imageNotifyFinishedCount);
   m_imageNotifyFinishedCount++;
   m_imageWidthOnImageNotifyFinished =
       m_content->hasImage() ? m_content->getImage()->width() : 0;
+  m_statusOnImageNotifyFinished = m_content->getStatus();
 }
 
 bool MockImageResourceObserver::imageNotifyFinishedCalled() const {
   DCHECK_LE(m_imageNotifyFinishedCount, 1);
   return m_imageNotifyFinishedCount;
 }
 
 }  // namespace blink