Add loading-reviews@ to core/html/parser watchlist.

BUG=

Review-Url: https://codereview.chromium.org/2192933002
Cr-Commit-Position: refs/heads/master@{#408548}

WATCHLISTS

@@ -1498,7 +1498,8 @@
                    'oilpan-reviews@chromium.org'],
     'blink_html': ['blink-reviews-html@chromium.org',
                    'dglazkov+blink@chromium.org'],
-    'blink_htmlparser': ['kinuko+watch@chromium.org'],
+    'blink_htmlparser': ['kinuko+watch@chromium.org',
+                         'loading-reviews+parser@chromium.org'],
     'blink_indexed_db': ['cmumford@chromium.org',
                          'jsbell+idb@chromium.org'],
     'blink_input': ['dtapuska+blinkwatch@chromium.org',