Revert of Media Galleries Partial Deprecation: Remove image metadata & libexif.

DEPS

 # This file is used to manage the dependencies of the Chromium src repo. It is
 # used by gclient to determine what version of each dependency to check out, and
 # where.
 #
 # For more information, please refer to the official documentation:
 #   https://sites.google.com/a/chromium.org/dev/developers/how-tos/get-the-code
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 #
@@ skipping 115 matching lines @@
 
   'src/third_party/angle':
    Var('chromium_git') + '/angle/angle.git' + '@' +  Var('angle_revision'),
 
   'src/third_party/colorama/src':
    Var('chromium_git') + '/external/colorama.git' + '@' + '799604a1041e9b3bc5d2789ecbd7e8db2e18e6b8',
 
   'src/third_party/icu':
    Var('chromium_git') + '/chromium/deps/icu.git' + '@' + '6d3b55dfa17d9a597c064eeef7ceac18c73184b7',
 
+  'src/third_party/libexif/sources':
+   Var('chromium_git') + '/chromium/deps/libexif/sources.git' + '@' + '9d467f7d21e4749ee22ee7520e561ac7b38484b9',
+
   'src/third_party/hunspell_dictionaries':
    Var('chromium_git') + '/chromium/deps/hunspell_dictionaries.git' + '@' + 'c106afdcec5d3de2622e19f1b3294c47bbd8bd72',
 
   'src/third_party/safe_browsing/testing':
     Var('chromium_git') + '/external/google-safe-browsing/testing.git' + '@' + '9d7e8064f3ca2e45891470c9b5b1dce54af6a9d6',
 
   'src/third_party/leveldatabase/src':
     Var('chromium_git') + '/external/leveldb.git' + '@' + '7306ef856a91e462a73ff1832c1fa8771008ba36',
 
   'src/third_party/snappy/src':
@@ skipping 698 matching lines @@
     'pattern': '\\.sha1',
     'action': ['python', 'src/third_party/instrumented_libraries/scripts/download_binaries.py'],
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/build/gyp_chromium'],
   },
 ]