[Resources] Add the Roboto font for contextual_search_promo_source and localize strings.

chrome/app/chromium_strings.grd

Index: chrome/app/chromium_strings.grd
diff --git a/chrome/app/chromium_strings.grd b/chrome/app/chromium_strings.grd
index 14e741fd859a67d9725e497ee97d35af461db7d2..70ce6c1fd1029f5bdc0e3891e6b20b7d146bdffe 100644
--- a/chrome/app/chromium_strings.grd
+++ b/chrome/app/chromium_strings.grd
@@ -1214,6 +1214,17 @@ Signing in anyway will merge Chromium information like bookmarks, history, and o
         </message>
       </if>
 
+      <!-- Contextual Search -->
+      <message name="IDS_CONTEXTUAL_SEARCH_PROMO_DESCRIPTION" desc="Description of the Contextual Search feature.">
+        Enabling "Tap to Search" provides an easy way to search for terms on a web page by simply tapping on them.  The word tapped and surrounding page will be sent to Google.
+      </message>
+      <message name="IDS_CONTEXTUAL_SEARCH_PROMO_OPTIN" desc="Text for the button the user clicks to opt in.">
+        Yes, please
+      </message>
+      <message name="IDS_CONTEXTUAL_SEARCH_PROMO_OPTOUT" desc="Text for the button the user clicks to opt out.">
+        No, thanks
+      </message>
+
       <!-- Update bubble -->
       <message name="IDS_REINSTALL_APP" desc="Text for the button the user clicks to reinstall the app.">
         Reinstall Chromium