Add setting to isolate zoom changes by default.

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- Main Page -->
   <if expr="chromeos">
     <message name="IDS_SETTINGS_SECONDARY_USER_BANNER" desc="Banner displayed in settings page when the user is secondary in a multi-profile session.">
       Some settings belonging to <ph name="PRIMARY_EMAIL">$1<ex>john@google.com</ex></ph> are being shared with you. These settings only affect your account when using multiple sign-in.
     </message>
   </if>
 
@@ skipping 1777 matching lines @@
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_MIDI_DEVICES_BLOCK" desc="The block label for MIDI devices in site settings.">
     Do not allow any sites to use system exclusive messages to access MIDI devices
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_USB_DEVICES" desc="Label for the USB devices in site settings.">
     USB devices
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_ZOOM_LEVELS" desc="Label for the Zoom levels category in site settings.">
     Zoom levels
   </message>
+  <message name="IDS_SETTINGS_SITE_SETTINGS_ZOOM_SCOPE_ORIGIN" desc="Label of the toggle to enable/disable having the user's zoom changes apply to all tabs that navigate to the origin that was zoomed. This is shown when the toggle is enabled.">
+    When you change a page's zoom, remember the change for all tabs on the same site (recommended)
+  </message>
+  <message name="IDS_SETTINGS_SITE_SETTINGS_ZOOM_SCOPE_TAB" desc="Label of the toggle to enable/disable having the user's zoom changes apply to all tabs that navigate to the origin that was zoomed. This is shown when the toggle is disabled. When it is disabled, zoom changes only apply to the one tab.">
+    When you change a page's zoom, do not zoom other tabs
+  </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_MAY_SAVE_COOKIES" desc="Label for the cookies option description site settings.">
     Sites can save and read cookie data
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_ASK_FIRST" desc="Label for ask first option in site settings.">
     Ask first
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_ASK_FIRST_RECOMMENDED" desc="The 'ask first' label in site settings -- a recommended setting for some categories, such as when sites want to use Geolocation.">
     Ask first (recommended)
   </message>
   <message name="IDS_SETTINGS_SITE_SETTINGS_ASK_BEFORE_ACCESSING" desc="The 'ask before accessing' label in site settings.">
@@ skipping 1070 matching lines @@
       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>