Add an API for hosted apps to check their install and running states.

chrome/test/data/extensions/get_app_details_for_frame.html

Index: chrome/test/data/extensions/get_app_details_for_frame.html
diff --git a/chrome/test/data/extensions/get_app_details_for_frame.html b/chrome/test/data/extensions/get_app_details_for_frame.html
index 81b4f2a56ed3a883938af42cccba4977ebd850cd..e878d85a8f95c4a2b3935b06d06a7f0e8ead202a 100644
--- a/chrome/test/data/extensions/get_app_details_for_frame.html
+++ b/chrome/test/data/extensions/get_app_details_for_frame.html
@@ -21,7 +21,14 @@ function getFrameURL(host) {
   return result;
 }
 
-var iframe = document.createElement("iframe");
-iframe.src = getFrameURL("app.com");
-document.documentElement.appendChild(iframe);
+function newFrame(host) {
+  if (frames.length > 0)
+    document.documentElement.removeChild(document.querySelector('iframe'));
+  var iframe = document.createElement("iframe");
+  iframe.src = getFrameURL(host);
+  document.documentElement.appendChild(iframe);
+}
+
+newFrame('app.com');
+
 </script>