Introduce a new 'all_frames' property to content scripts and

chrome/test/data/extensions/api_test/content_script_all_frames/test.html

+<script>
+// We load a page that has one iframe
+// So we should receive two "all_frames" messages, and one "top_frame_only"
+// messages.
+
+var num_all_frames_messages = 0;
+var num_top_frame_only_messages = 0;
+
+chrome.test.runTests([
+  // Tests receiving a request from a content script and responding.
+  function onRequest() {
+    chrome.extension.onRequest.addListener(
+      function(request, sender, sendResponse) {
+        if (request == "all_frames") {
+          num_all_frames_messages++;
+        } else if (request == "top_frame_only") {
+          num_top_frame_only_messages++;
+        } else {
+          chrome.test.fail("Unexpected request: " + JSON.stringify(request));
+        }
+
+        if (num_all_frames_messages == 2 && num_top_frame_only_messages == 1) {
+          chrome.test.succeed();
+        }
+      }
+    );
+  }
+]);
+
+chrome.test.log("Creating tab...");
+chrome.tabs.create({
+  url: "http://localhost:1337/files/extensions/test_file_with_iframe.html"
+});
+</script>