Add missing (and remove superfluous) 'explicit' from constructors.

media/ffmpeg/ffmpeg_regression_tests.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.
 //
 // Regression tests for FFmpeg.  Security test files can be found in the
 // internal media test data directory:
 //
 //    svn://svn.chromium.org/chrome-internal/trunk/data/media/security/
 //
 // Simply add the custom_dep below to your gclient and sync:
@@ skipping 42 matching lines @@
   const char* video_md5;
   const char* audio_md5;
   const char* filename;
   PipelineStatus init_status;
   PipelineStatus end_status;
 };
 
 // Used for tests which just need to run without crashing or tooling errors, but
 // which may have undefined behavior for hashing, etc.
 struct FlakyRegressionTestData {
-  FlakyRegressionTestData(const char* filename)
+  explicit FlakyRegressionTestData(const char* filename)
       : filename(filename) {
   }
 
   const char* filename;
 };
 
 class FFmpegRegressionTest
     : public testing::TestWithParam<RegressionTestData>,
       public PipelineIntegrationTestBase {
 };
@@ skipping 284 matching lines @@
 }
 
 TEST_P(FlakyFFmpegRegressionTest, BasicPlayback) {
   if (Start(GetTestDataFilePath(GetParam().filename))) {
     Play();
     WaitUntilEndedOrError();
   }
 }
 
 }  // namespace media