Add message and Help Center link to the chooser UI

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 430376412f23a82413293fec4cdf86317c23f71b..a8f9f3d4ed90e2def77b2624adbc292352221461 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -14563,6 +14563,14 @@ Please check your email at <ph name="ACCOUNT_EMAIL">$2<ex>jane.doe@gmail.com</ex
       <message name="IDS_CHOOSER_BUBBLE_CANCEL_BUTTON_TEXT" desc="The text that is shown on the cancel button in the chooser popup.">
         Cancel
       </message>
+      <!-- Chooser Bubble No Device Text -->
+      <message name="IDS_CHOOSER_BUBBLE_NO_DEVICE_TEXT" desc="This text is shown at the bottom of the chooser popup.">
+        Not seeing your device?
+      </message>
+      <!-- Chooser Bubble Get Help Link Text -->
+      <message name="IDS_CHOOSER_BUBBLE_GET_HELP_LINK_TEXT" desc="This text is shown at the bottom of the chooser popup and links to a Help Center URL.">
+        Get help

[Jeffrey Yasskin, 2016/02/17 01:33:45]

Putting two strings next to each other tends to be bad for internationalization.
I don't have a concrete example where this one will cause problems, but it's
dangerous in general.

It looks like views::StyledLabel is the class to use for labels where part of
the string is supposed to be linked.
https://code.google.com/p/chromium/codesearch/#chromium/src/chrome/browser/ch...
has an example of doing this sort of embedding. It's not quite as nice as
Android's parsed messages
(https://code.google.com/p/chromium/codesearch/#chromium/src/chrome/android/ja...
and
https://code.google.com/p/chromium/codesearch/#chromium/src/chrome/android/ja...),
but it's better than freezing the order in code.

[juncai, 2016/02/17 22:40:40]

Done.

+      </message>
     </if>
 
     <if expr="is_android">