Add a watchlist for XML; update custom elements.

WATCHLISTS

Index: WATCHLISTS
diff --git a/WATCHLISTS b/WATCHLISTS
index 9c5da177e69830f457b55cc0fa59d3c3c218a39f..a911c7649841f7f8d25a46e112b047a9233e00a4 100644
--- a/WATCHLISTS
+++ b/WATCHLISTS
@@ -1036,7 +1036,7 @@
                   '|third_party/WebKit/LayoutTests/platform/chromium.*/fast/regions/'
     },
     'blink_custom_elements': {
-      'filepath': 'third_party/WebKit/Source/core/dom/CustomElement' \
+      'filepath': 'third_party/WebKit/Source/core/dom/custom/' \
                   '|third_party/WebKit/Source/bindings/v8/.*CustomElement',
     },
     'blink_device_light': {
@@ -1296,6 +1296,11 @@
                   '|content/test/layouttest_support.cc' \
                   '|content/public/test/layouttest_support.h' \
     },
+    'xml': {
+      'filepath': 'third_party/WebKit/Source/core/xml/' \
+                  '|third_party/libxml/' \
+                  '|third_party/libxslt/',
+    },
   },
 
   'WATCHLISTS': {
@@ -1838,5 +1843,6 @@
     'test_runner': [ 'jochen+watch@chromium.org',
                      'mlamouri+watch-test-runner@chromium.org' ],
     'clank_uma_settings': ['gayane+watch@chromium.org'],
+    'xml': [ 'dominicc+watchlist@chromium.org' ],
   },
 }