Add IPCs to check web copy/cut/paste for extensions with the appropriate permission bit.

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

 // Clipboard API test for Chrome.
 // browser_tests.exe --gtest_filter=ExtensionApiTest.Clipboard
 
 const TEST_URL_TMPL = "http://localhost:PORT/files/extensions/test_file.html";
 
 chrome.test.getConfig(function(config) {
 
   var TEST_URL = TEST_URL_TMPL.replace(/PORT/, config.testServer.port);
 
   function setupWindow(callback) {
@@ skipping 47 matching lines @@
               chrome.test.callbackPass());
           } else if (request == "paste event") {
             onRequestCompleted();
           } else {
             chrome.test.fail("Unexpected request: " + JSON.stringify(request));
           }
         }
       );
       setupWindow();
     },
+    function domCopy() {
+      document.body.addEventListener('copy', chrome.test.callbackPass());
+      document.execCommand('copy');
+    },
     function domPaste() {
       document.body.addEventListener('paste', chrome.test.callbackPass());
       document.execCommand('paste');
     }
   ]);
 });