Functionality has been requested in the Extension API for Javascript to...

chrome/renderer/extensions/extension_api_client_unittest.cc

Index: chrome/renderer/extensions/extension_api_client_unittest.cc
===================================================================
--- chrome/renderer/extensions/extension_api_client_unittest.cc	(revision 20805)
+++ chrome/renderer/extensions/extension_api_client_unittest.cc	(working copy)
@@ -422,6 +422,18 @@
                "RemoveTab", "2");
 }
 
+TEST_F(ExtensionAPIClientTest, GetVisibleTabCapture) {
+  ExpectJsFail("chrome.tabs.getVisibleTabCapture(0);",
+               "Uncaught Error: Parameter 1 is required.");
+
+  ExpectJsFail("chrome.tabs.getVisibleTabCapture(function(){}, 0)",
+               "Uncaught Error: Invalid value for argument 0. "
+               "Expected 'integer' but got 'function'.");
+
+  ExpectJsPass("chrome.tabs.getVisibleTabCapture(null, function(img){});",
+               "GetVisibleTabCapture", "null");
+}
+
 // Bookmark API tests
 // TODO(erikkay) add more variations here