Adding visualmetrics code under third_party for speedindex calculations.

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 265 matching lines @@
 
   'src/third_party/openh264/src':
     Var('chromium_git') + '/external/github.com/cisco/openh264' + '@' + 'b37cda248234162033e3e11b0335f3131cdfe488',
 
   'src/third_party/re2/src':
     Var('chromium_git') + '/external/github.com/google/re2.git' + '@' + 'dba3349aba83b5588e85e5ecf2b56c97f2d259b7',
 
   # Used for building libFuzzers (only supports Linux).
   'src/third_party/libFuzzer/src':
     Var('chromium_git') + '/chromium/llvm-project/llvm/lib/Fuzzer.git' + '@' +  Var('libfuzzer_revision'),
+
+  'src/third_party/visualmetrics/src':
+    Var('chromium_git') + '/external/github.com/WPO-Foundation/visualmetrics.git' + '@' +  '1edde9d2fe203229c895b648fdec355917200ad6',
 }
 
 
 deps_os = {
   'win': {
     'src/third_party/cygwin':
      Var('chromium_git') + '/chromium/deps/cygwin.git' + '@' + 'c89e446b273697fadf3a10ff1007a97c0b7de6df',
 
     'src/third_party/psyco_win32':
      Var('chromium_git') + '/chromium/deps/psyco_win32.git' + '@' + 'f5af9f6910ee5a8075bbaeed0591469f1661d868',
@@ skipping 658 matching lines @@
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/build/gyp_chromium', '--running-as-hook'],
   },
 ]
 
 # ANGLE manages DEPS that it also owns the build files for, such as dEQP.
 recursedeps = [("src/third_party/angle", "DEPS.chromium")]