Browser tests for OOPIF support for drag-n-drop.

content/test/data/drag_and_drop/event_monitoring.js

Index: content/test/data/drag_and_drop/event_monitoring.js
diff --git a/content/test/data/drag_and_drop/event_monitoring.js b/content/test/data/drag_and_drop/event_monitoring.js
new file mode 100644
index 0000000000000000000000000000000000000000..3b39e98f7f1bace01bf9a9389fb214cc3293853d
--- /dev/null
+++ b/content/test/data/drag_and_drop/event_monitoring.js
@@ -0,0 +1,33 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/* Reports an event to DragAndDropBrowserTest and  DOMDragEventWaiter */
+window.reportDragAndDropEvent = function(ev) {
+  function safe(f) {
+    try {
+      return f();
+    } catch(err) {
+      return "exception: " + err.message;
+    }
+  }
+
+  console.log("got event: " + ev.type);
+
+  window.domAutomationController.setAutomationId(0);

[Łukasz Anforowicz, 2016/11/01 23:43:42]

The line above tells the renderer to enable window.domAutomationController.send
to send IPCs to the browser.  The exact value of the argument (0) is mostly
ignored (see DOMAutomationController::automation_id_) and only distinguishes
"armed" (!= MSG_ROUTING_NONE) and "disarmed / already responded" (==
MSG_ROUTING_NONE).  Blocking IPCs via setAutomationId is useful for a
fire-once-only ExecuteScriptAndExtractString (although for a request/response we
should instead send some kind of a nonce - with the current scheme unrelated
messages/responses can still get through).

As a follow-up I want to try removing the setAutomationId method altogether.  In
most cases it seems to be always followed by an almost immediate
window.domAutomationController.send call.

+  window.domAutomationController.send({
+    drop_effect: safe(function() { return ev.dataTransfer.dropEffect; }),
+    effect_allowed: safe(function() { return ev.dataTransfer.effectAllowed; }),
+    event_type: ev.type,
+    file_names: safe(function() {
+      return Array
+          .from(ev.dataTransfer.files)
+          .map(function(file) { return file.name; })
+          .sort().join();
+    }),
+    mime_types: safe(function() {
+      return Array.from(ev.dataTransfer.types).sort().join();
+    }),
+    window_name: window.name
+  });
+}