Replace NULL with nullptr in all C++ files.

webrtc/tools/frame_analyzer/video_quality_analysis_unittest.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 12 matching lines @@
 namespace test {
 
 // Setup a log file to write the output to instead of stdout because we don't
 // want those numbers to be picked up as perf numbers.
 class VideoQualityAnalysisTest : public ::testing::Test {
  protected:
   static void SetUpTestCase() {
     std::string log_filename = webrtc::test::OutputPath() +
         "VideoQualityAnalysisTest.log";
     logfile_ = fopen(log_filename.c_str(), "w");
-    ASSERT_TRUE(logfile_ != NULL);
+    ASSERT_TRUE(logfile_ != nullptr);
   }
   static void TearDownTestCase() {
     ASSERT_EQ(0, fclose(logfile_));
   }
   static FILE* logfile_;
 };
-FILE* VideoQualityAnalysisTest::logfile_ = NULL;
+FILE* VideoQualityAnalysisTest::logfile_ = nullptr;
 
 TEST_F(VideoQualityAnalysisTest, MatchExtractedY4mFrame) {
   std::string video_file =
          webrtc::test::ResourcePath("reference_less_video_test_file", "y4m");
 
   std::string extracted_frame_from_video_file =
          webrtc::test::ResourcePath("video_quality_analysis_frame", "txt");
 
   int frame_height = 720, frame_width = 1280;
   int frame_number = 2;
@@ skipping 77 matching lines @@
   stats_file << "frame_0004 0106\n";
   stats_file.close();
 
   PrintMaxRepeatedAndSkippedFrames(logfile_, "NormalStatsFile",
                                    stats_filename_ref, stats_filename);
 }
 
 
 }  // namespace test
 }  // namespace webrtc