Fix Typo in cookie controls message description

Tbr: huanzhong@chromium.org
Bug: 967668
Change-Id: I5757ac0dda9f33875a08d92a3c1927b3a7d3c3b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1808846Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697277}

chrome/app/generated_resources.grd

@@ -2492,7 +2492,7 @@ are declared in tools/grit/grit_rule.gni.
       <message name="IDS_COOKIE_CONTROLS_TURN_ON_BUTTON" desc="Label shown on a button that turns cookie blocking on after it was disabled for a specific site.">
         Turn on
       </message>
-      <message name="IDS_COOKIE_CONTROLS_TURN_OFF_BUTTON" desc="Label shown on a button that turns of cookie blocking for a specific site.">
+      <message name="IDS_COOKIE_CONTROLS_TURN_OFF_BUTTON" desc="Label shown on a button that turns off cookie blocking for a specific site.">
         Turn off for this site
       </message>
       <message name="IDS_COOKIE_CONTROLS_BLOCKED_MESSAGE" desc="Text shown in the dialog that allows users to control cookie blocking. Shows the number of sites for which cookies have been blocked.">