Add media file validation to utility process

media/media.gyp

Index: media/media.gyp
diff --git a/media/media.gyp b/media/media.gyp
index b2bde3dc872aebb3e719a9345f9e1390844061c8..c0a08e4b86ab71c1bfbd17add68b169f9d7aa911 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -261,6 +261,8 @@
         'base/filter_collection.h',
         'base/media.cc',
         'base/media.h',
+        'base/media_file_checker.cc',
+        'base/media_file_checker.h',
         'base/media_keys.cc',
         'base/media_keys.h',
         'base/media_log.cc',
@@ -466,6 +468,8 @@
           'sources!': [
             'base/container_names.cc',
             'base/container_names.h',
+            'base/media_file_checker.cc',
+            'base/media_file_checker.h',
             'base/media_posix.cc',
             'ffmpeg/ffmpeg_common.cc',
             'ffmpeg/ffmpeg_common.h',
@@ -926,6 +930,7 @@
         'base/decoder_buffer_unittest.cc',
         'base/djb2_unittest.cc',
         'base/gmock_callback_support_unittest.cc',
+        'base/media_file_checker_unittest.cc',
         'base/multi_channel_resampler_unittest.cc',
         'base/pipeline_unittest.cc',
         'base/ranges_unittest.cc',
@@ -998,6 +1003,10 @@
           'dependencies': [
             '../third_party/ffmpeg/ffmpeg.gyp:ffmpeg',
           ],
+        }, {  # media_use_ffmpeg== 0
+          'sources!': [
+            'base/media_file_checker_unittest.cc',
+          ],
         }],
         ['os_posix==1 and OS!="mac" and OS!="ios"', {
           'conditions': [