Convert most geolocation layout tests to use a JS mock implementation.

third_party/WebKit/LayoutTests/fast/dom/Geolocation/script-tests/cached-position-iframe.js

-description('Tests that a cached position can be obtained in one frame after another frame has received a fresh position.');
-
-if (!window.testRunner || !window.internals)
-    debug('This test can not run without testRunner or internals');
-
-internals.setGeolocationClientMock(document);
-internals.setGeolocationPosition(document, 51.478, -0.166, 100);
-internals.setGeolocationPermission(document, true);
-
-window.onmessage = function (messageEvent) {
-    debug(messageEvent.data.message);
-    success = messageEvent.data.success;
-    shouldBeTrue('success');
-    finishJSTest();
-}
-
-navigator.geolocation.getCurrentPosition(
-    function() {
-        // Kick off the iframe to request a cached position. The iframe
-        // will post a message back on success / failure.
-        iframe = document.createElement('iframe');
-        iframe.src = 'resources/cached-position-iframe-inner.html';
-        document.body.appendChild(iframe);
-    });
-
-window.jsTestIsAsync = true;