Add <a is="action-link">, a web component extension of <a> for in-page actions.

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 7c45527ee719f473be625ec923fbf15f4ee99dcd..9b889feaad6afa5310fc10d3b5fd6cace0a2fadd 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -13471,7 +13471,7 @@ Some features may be unavailable.  Please check that the profile exists and you
         Oops! The new supervised user couldn't be created. Please make sure you're signed in properly and try again.
       </message>
       <message name="IDS_PROFILES_CREATE_EXISTING_SUPERVISED_USER_ERROR" desc="Message shown when the user enters the name of a supervised user that can be imported.">
-        Looks like you're already managing a user by that name.<ph name="LINE_BREAK">&lt;br/&gt;</ph>Did you want to <ph name="BEGIN_LINK">&lt;button id="supervised-user-import-existing" class="link-button"&gt;</ph>import <ph name="PROFILE_NAME">$1<ex>John</ex></ph> to this device<ph name="END_LINK">&lt;/button&gt;</ph>?
+        Looks like you're already managing a user by that name.<ph name="LINE_BREAK">&lt;br/&gt;</ph>Did you want to <ph name="BEGIN_LINK">&lt;a is="action-link" id="supervised-user-import-existing"&gt;</ph>import <ph name="PROFILE_NAME">$1<ex>John</ex></ph> to this device<ph name="END_LINK">&lt;/a&gt;</ph>?
       </message>
       <message name="IDS_PROFILES_CREATE_SUPERVISED_SIGNED_IN_LABEL" desc="Label for the 'Supervised user' checkbox in the create-profile dialog when the current user is signed in.">
         Control and view the websites this person visits from <ph name="CUSTODIAN_EMAIL">$1<ex>user@gmail.com</ex></ph>.
@@ -13484,7 +13484,7 @@ Some features may be unavailable.  Please check that the profile exists and you
         Creating your supervised user. This may take a few moments.
       </message>
       <message name="IDS_PROFILES_CREATE_SUPERVISED_NOT_SIGNED_IN_HTML" desc="Label for the (disabled) 'Supervised user' checkbox in the create-profile dialog when the current user is not signed in, containing a link to the sign in page.">
-        <ph name="BEGIN_SIGN_IN_LINK">&lt;button id="create-profile-supervised-sign-in-link" class="link-button"&gt;</ph>Sign in<ph name="END_SIGN_IN_LINK">&lt;/button&gt;</ph> to control and view the websites this person visits.
+        <ph name="BEGIN_SIGN_IN_LINK">&lt;a is="action-link" id="create-profile-supervised-sign-in-link"&gt;</ph>Sign in<ph name="END_SIGN_IN_LINK">&lt;/a&gt;</ph> to control and view the websites this person visits.
       </message>
       <message name="IDS_PROFILES_CREATE_SUPERVISED_NOT_SIGNED_IN_LINK" desc="Text for the sign-in promo link, shown after the (disabled) 'Supervised user' checkbox in the create-profile dialog when the current user is not signed in.">
         Sign in now