Adds us(intl_pc) IME to xkb extension.

chrome/browser/resources/chromeos/input_method/google_xkb_manifest.json

 {
   "name": "Chrome OS XKB",
   "version": "1.0.5.0",
   "description": "Chrome OS XKB",
   "default_locale": "en",
   "incognito": "split",
   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7C0oB6YTnf69uhWnVTZl5TB/psHrJXgIPLYchFb0whlVCG8fqMo9lW/oxBmZXZ3N8T7zZrdYI/SUjoc9I5R/dMVVD2q4iKox+x7xlTbqSdVeOb6b9ZVJ24pLbO1L7feSNSBgR0t61jrC2eY/gf78h7w58UEQBPFT2mUxhhwodyQIDAQAB",
   "permissions": [
     "accessibilityFeatures.read",
     "app.window.alpha",
@@ skipping 97 matching lines @@
         "en",
         "en-US"
       ],
       "layouts": [
         "us(intl)"
       ],
       "input_view": "inputview.html#id=us-intl&language=en-US&passwordLayout=us-intl&name=keyboard_us_international",
       "options_page": "hmm_options.html?code=xkb:us:intl:eng"
     },
     {
+      "name": "__MSG_keyboard_us_international_pc__",
+      "type": "ime",
+      "id": "xkb:us:intl_pc:eng",
+      "indicator": "INTL",
+      "description": "",
+      "language": [
+        "en",
+        "en-US"

[Shu Chen, 2017/06/19 07:15:26]

We need to at first confirm which languages need the intl_pc behavior.
I recall pt-BR needs it.

+      ],
+      "layouts": [
+        "us(intl)"

[Shu Chen, 2017/06/19 07:15:26]

should be us(intl_pc)

+      ],
+      "input_view": "inputview.html#id=us-intl&language=en-US&passwordLayout=us-intl&name=keyboard_us_international_pc",
+      "options_page": "hmm_options.html?code=xkb:us:intl_pc:eng"
+    },
+    {
       "name": "__MSG_keyboard_netherlands__",
       "type": "ime",
       "id": "xkb:us:intl:nld",
       "indicator": "NLD",
       "description": "",
       "language": [
         "nl"
       ],
       "layouts": [
         "us(intl)"
@@ skipping 1756 matching lines @@
         "ru"
       ],
       "layouts": [
         "us"
       ],
       "input_view": "inputview.html#id=m17n:ru_phone_yazhert&language=ru&passwordLayout=us-ltr&name=keyboard_russian_phonetic_yazhert"
     }
   ],
   "manifest_version": 2
 }