Fix comments in ShellUtil::MakeChromeDefaultProtocolClient

Change-Id: I8f8c232c5916da49dff2b2c1251f9c48f598a31a
Reviewed-on: https://chromium-review.googlesource.com/691157
Commit-Queue: Greg Thompson <grt@chromium.org>
Reviewed-by: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505326}

chrome/installer/util/shell_util.cc

@@ -2082,7 +2082,7 @@ bool ShellUtil::MakeChromeDefaultProtocolClient(
 
   // Windows 8 does not permit making a browser default just like that.
   // This process needs to be routed through the system's UI. Use
-  // ShowMakeChromeDefaultProocolClientSystemUI instead (below).
+  // ShowMakeChromeDefaultProtocolClientSystemUI instead (below).
   if (!CanMakeChromeDefaultUnattended())
     return false;