Allow secondary tiles to be unpinned.

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 c8e8781fbc8b276ef162397b86a2513851338bfa..2faf49668adfb033ca350e3942d1362ce4597da1 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -948,6 +948,9 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
         <message name="IDS_PIN_TO_START_SCREEN" desc="The text label of the Pin to start screen menu item">
           Pin to Start Screen
         </message>
+        <message name="IDS_UNPIN_FROM_START_SCREEN" desc="The text label of the unpin from start screen menu item">
+          Unpin from Start Screen
+        </message>
         <message name="IDS_EDIT2" desc="The text label before the cut/copy/paste buttons in the merged menu">
           Edit
         </message>
@@ -1037,6 +1040,9 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
         <message name="IDS_PIN_TO_START_SCREEN" desc="In Title Case: The text label of the Pin to start screen menu item">
           Pin to Start Screen
         </message>
+        <message name="IDS_UNPIN_FROM_START_SCREEN" desc="In Title Case: The text label of the Unpin from start screen menu item">
+          Unpin from Start Screen
+        </message>
         <message name="IDS_UNDO" desc="In Title Case: The text label of the Undo menu item">
           &amp;Undo
         </message>