Roll chromium_revision 7f405ec2b6..4b42aa218b (411933:411951)

DEPS

 # This file contains dependencies for WebRTC that are not shared with Chromium.
 # If you wish to add a dependency that is present in Chromium's src/DEPS or a
 # directory from the Chromium checkout, you should add it to setup_links.py
 # instead.
 
 vars = {
   'extra_gyp_flag': '-Dextra_gyp_flag=0',
   'chromium_git': 'https://chromium.googlesource.com',
-  'chromium_revision': '7f405ec2b6914d482d081d2cb5d80bdf5226bd57',
+  'chromium_revision': '4b42aa218b8ebeef9ef8eef3109df7d89214d38d',
 }
 
 # NOTE: Use http rather than https; the latter can cause problems for users
 # behind proxies.
 deps = {
   'src/third_party/gflags/src':
     Var('chromium_git') + '/external/github.com/gflags/gflags@03bebcb065c83beff83d50ae025a55a4bf94dfca',
 }
 
 deps_os = {
@@ skipping 65 matching lines @@
   },
   {
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     'name': 'gyp',
     'pattern': '.',
     'action': ['python', 'src/webrtc/build/gyp_webrtc.py',
                Var('extra_gyp_flag')],
   },
 ]