Enable all ESC-Fullscreen tests (Chrome Apps) for all platforms.

chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js

Index: chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js
diff --git a/chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js b/chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js
index 109bccf88f97724024efc2dab190a1b785632da4..1c9d42595825fa5fac28bcf39d92408b09b7a846 100644
--- a/chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js
+++ b/chrome/test/data/extensions/platform_apps/leave_fullscreen/main.js
@@ -14,6 +14,13 @@ chrome.app.runtime.onLaunched.addListener(function() {
     });
 
     chrome.test.sendMessage('Launched', function(reply) {
+      win.contentWindow.document.addEventListener('keydown', function(e) {
+        if (e.keyCode != 90) // 'z'

[koz (OOO until 15th September), 2014/01/08 23:29:25]

'z' is 122, 'Z' is 90. Consider using 'Z'.charCodeAt(0) instead of 90.

[mlamouri (slow - plz ping), 2014/01/09 17:08:46]

keyCode and charCode are not the same thing and I would prefer not to try to
find a relationship between DOM KeyEvents and ECMAScript char codes.

+          return;
+
+        chrome.test.sendMessage('KEY_RECEIVED');

[koz (OOO until 15th September), 2014/01/08 23:29:25]

nit: The other messages are in camel case so this should probably be
'KeyReceived'.

[mlamouri (slow - plz ping), 2014/01/09 17:08:46]

Done.

+      });
+
       switch (reply) {
         case 'window':
           win.fullscreen();