Make the dismiss button on the CF infobar be an image button.

chrome/app/google_chrome_strings.grd

Index: chrome/app/google_chrome_strings.grd
diff --git a/chrome/app/google_chrome_strings.grd b/chrome/app/google_chrome_strings.grd
index eb892d3cba1f034cc3cf5bf8d511a0514454c7ae..b32270be963af478fb7e4f73bf9233f16e4a62ef 100644
--- a/chrome/app/google_chrome_strings.grd
+++ b/chrome/app/google_chrome_strings.grd
@@ -196,10 +196,10 @@ Chrome supports. -->
         </message>
         <message name="IDS_CHROME_FRAME_TURNDOWN_TEXT_IE_OLDER" desc="Text of Chrome Frame turndown prompt for IE 6, 7, and 8">
           This site is using the Chrome Frame plug-in which will soon be unsupported. Please uninstall it and upgrade to a modern browser.
-	</message>
+        </message>
         <message name="IDS_CHROME_FRAME_TURNDOWN_TEXT_IE_NEWER" desc="Text of Chrome Frame turndown prompt for IE 9 and 10">
           This site is using the Chrome Frame plug-in that will soon be unsupported. Please uninstall it and download a compatible browser.
-	</message>
+        </message>
         <message name="IDS_SHORTCUT_NEW_WINDOW" desc="The text label of the New window shortcut context menu entry as of Windows 8">
           New window
         </message>