MD Settings: Dual-role charger selection

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- About Page -->
   <message name="IDS_SETTINGS_ABOUT_PAGE_BROWSER_VERSION" desc="The text label describing the version of the browser, example: Version 57.0.2937.0 (Developer Build) unknown (64-bit)">
     Version <ph name="PRODUCT_VERSION">$1<ex>15.0.865.0</ex></ph> (<ph name="PRODUCT_CHANNEL">$2<ex>Developer Build</ex></ph>) <ph name="PRODUCT_MODIFIER">$3</ph> <ph name="PRODUCT_VERSION_BITS">$4</ph>
   </message>
   <if expr="chromeos">
     <message name="IDS_SETTINGS_ABOUT_PAGE_DETAILED_BUILD_INFO" desc="Label describing the section that shows detailed information about the current Chrome build.">
       Detailed build information
@@ skipping 2726 matching lines @@
     </message>
     <message name="IDS_SETTINGS_STORAGE_CLEAR_DRIVE_CACHE_DIALOG_TITLE" desc="Title for the storage manager confirmation dialog tab to remove Google Drive offline files.">
       Delete offline files?
     </message>
     <message name="IDS_SETTINGS_STORAGE_CLEAR_DRIVE_CACHE_DESCRIPTION" desc="Description in the storage manager confirmation dialog to remove Google Drive offline files.">
       Temporary Google Drive offline files will be deleted. Files that you’ve set as available offline won’t be deleted from this device.
     </message>
     <message name="IDS_SETTINGS_STORAGE_DELETE_ALL_BUTTON_TITLE" desc="In storage manager confirmation dialog, label for the button to delete offline files.">
       Delete files
     </message>
+
+    <!-- Power -->
+    <message name="IDS_SETTINGS_POWER_SOURCE_LABEL" desc="The label for the power source dropdown in the Power overlay.">
+      Power source
+    </message>
+    <message name="IDS_SETTINGS_POWER_SOURCE_BATTERY" desc="The text referring to the battery as the power source.">
+      Battery
+    </message>
+    <message name="IDS_SETTINGS_POWER_SOURCE_AC_ADAPTER" desc="The text referring to a dedicated charger like an AC adapter as the power source.">
+      AC adapter
+    </message>
+    <message name="IDS_SETTINGS_POWER_SOURCE_LOW_POWER_CHARGER" desc="The text referring to a low-power charger like a USB charger as the power source.">
+      Low-power charger
+    </message>
+    <message name="IDS_SETTINGS_POWER_SOURCE_CALCULATING" desc="The description in the 'Power' overlay when the power status is being determined.">
+      Checking...
+    </message>
   </if>
 
   <!-- System Page -->
   <if expr="not chromeos">
     <message name="IDS_SETTINGS_SYSTEM" desc="Title of the system settings.">
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_BUTTON" desc="Text for the button that changes a user's network proxy settings.">
       Change proxy settings
     </message>
   </if>
 </grit-part>