Revert "Remove all safesync_url functionality from gclient"

recipe_modules/gclient/example.expected/tryserver.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "config",
       "--spec",
       "cache_dir = '[ROOT]/git_cache'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'src', 'url': 'https://chromium.googlesource.com/chromium/src.git'}]"
     ],
@@ skipping 69 matching lines @@
     },
     "name": "gclient recurse (git config user.email)"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "config",
       "--spec",
-      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'WebKit', 'url': 'svn://svn.chromium.org/blink/trunk'}]"
+      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': 'DEPS', 'managed': True, 'name': 'WebKit', 'safesync_url': 'https://blink-status.appspot.com/lkgr', 'url': 'svn://svn.chromium.org/blink/trunk'}]"
     ],
     "cwd": "[SLAVE_BUILD]/src/third_party",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "[spec: WebKit] gclient setup"
   },
   {
     "cmd": [
       "python",
@@ skipping 10 matching lines @@
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "sync",
       "--nohooks",
       "--force",
       "--verbose",
       "--delete_unversioned_trees",
       "--with_branch_heads",
       "--revision",
-      "WebKit@HEAD",
-      "--revision",
       "third_party/WebKit@123",
       "--output-json",
       "/path/to/tmp/json"
     ],
     "cwd": "[SLAVE_BUILD]/src/third_party",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "[spec: WebKit] gclient sync",
     "~followup_annotations": [
@@ skipping 46 matching lines @@
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]