Copy chromium.webkit:WebKit Win10 to chromium.win (2).

Mark the original master as chromium.webkit and add
testing/buildbot changes.

BUG=790343

Change-Id: I11f61b9100f0879c9cb6d63119d7d508a9d779c7
Reviewed-on: https://chromium-review.googlesource.com/c/1262677Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Jao-ke Chin-Lee <jchinlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597318}

infra/config/global/cr-buildbucket.cfg

@@ -2417,7 +2417,8 @@ buckets {
     builders {
       name: "WebKit Win10"
       dimensions: "os:Windows-10"
-      mixins: "webkit-ci"
+      mixins: "win-ci"
+      mixins: "webkit-ci-migration"
     }
     builders {
       name: "win32-dbg"

testing/buildbot/chromium.win.json

 {
   "AAAAA1 AUTOGENERATED FILE DO NOT EDIT": {},
   "AAAAA2 See generate_buildbot_json.py to make changes": {},
+  "WebKit Win10": {
+    "isolated_scripts": [
+      {
+        "args": [
+          "--num-retries=3"
+        ],
+        "isolate_name": "webkit_layout_tests_exparchive",
+        "merge": {
+          "args": [
+            "--verbose"
+          ],
+          "script": "//third_party/blink/tools/merge_web_test_results.py"
+        },
+        "name": "webkit_layout_tests",
+        "results_handler": "layout tests",
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "os": "Windows-10-15063"
+            }
+          ],
+          "shards": 12
+        }
+      }
+    ]
+  },
   "Win 7 Tests x64 (1)": {
     "gtest_tests": [
       {

testing/buildbot/waterfalls.pyl

@@ -3450,6 +3450,8 @@
           ],
         },
       },
+      # TODO(jchinlee): This builder is in chromium.win on LUCI, see
+      # crbug.com/790343.
       'WebKit Win10': {
         'test_suites': {
           'isolated_scripts': 'chromium_webkit_isolated_scripts',
@@ -3656,6 +3658,11 @@
   {
     'name': 'chromium.win',
     'machines': {
+      'WebKit Win10': {
+        'test_suites': {
+          'isolated_scripts': 'chromium_webkit_isolated_scripts',
+        },
+      },
       'Win 7 Tests x64 (1)': {
         'test_suites': {
           'gtest_tests': 'chromium_win_gtests',