Enable CSP by default for extensions with manifest_version >= 2.

chrome/test/data/extensions/api_test/default_content_security_policy/test.js

Index: chrome/test/data/extensions/api_test/default_content_security_policy/test.js
===================================================================
--- chrome/test/data/extensions/api_test/default_content_security_policy/test.js	(revision 0)
+++ chrome/test/data/extensions/api_test/default_content_security_policy/test.js	(revision 0)
@@ -0,0 +1,21 @@
+window.externalCanary = "Alive";
+
+chrome.test.getConfig(function(config) {
+
+  function inlineScriptDoesNotRun() {
+    chrome.test.assertEq(window.inlineCanary, undefined);
+    chrome.test.runNextTest();
+  }
+
+  function externalScriptDoesRun() {
+    // This test is somewhat zen in the sense that if external scripts are
+    // blocked, we don't be able to even execute the test harness...
+    chrome.test.assertEq(window.externalCanary, "Alive");
+    chrome.test.runNextTest();
+  }
+
+  chrome.test.runTests([
+    inlineScriptDoesNotRun,
+    externalScriptDoesRun
+  ]);
+});