Create the base Custom Context Menu Dialog.

chrome/android/java/strings/android_chrome_strings.grd

Index: chrome/android/java/strings/android_chrome_strings.grd
diff --git a/chrome/android/java/strings/android_chrome_strings.grd b/chrome/android/java/strings/android_chrome_strings.grd
index 1159cb81e2253b67feebb2a22fdefc826b163480..cf41bf0b7230e216871faae897a529065be7cf70 100644
--- a/chrome/android/java/strings/android_chrome_strings.grd
+++ b/chrome/android/java/strings/android_chrome_strings.grd
@@ -2779,6 +2779,12 @@ You must have Bluetooth and Location turned on in order to use the Physical Web.
       <message name="IDS_CONTEXTMENU_VIDEO_TITLE" desc="The title of a context menu tab when the item pressed contains more than one type. This indicates that all the actions are related to a video.">
         VIDEO
       </message>
+      <message name="IDS_CONTEXT_MENU_ROW_ICON_DESCRIPTION" desc="The description of the icon next to an item in a context menu. For example 'Open In New Tab Icon' or 'Download Image icon.' This is used for a the description of the icon for accessability purposes.">
+        <ph name="MENU_ITEM">%1$s<ex>Open in new tab</ex></ph> icon
+      </message>
+      <message name="IDS_CONTEXT_MENU_ROW_SHARE_ICON_DESCRIPTION" desc="The description of the icon next to the share menu item within a context menu.">

[Ted C, 2017/03/28 17:31:44]

we can remove this from this patch as well.  we should also just consider using
accessibility_menu_share_via as the content description for this.

[JJ, 2017/03/28 21:16:12]

Done.

+        An icon that represents the most recently used app when sharing in Chrome.
+      </message>
     </messages>
   </release>
 </grit>