Allow out-of-process iframes to update the mouse cursor

content/browser/site_per_process_browsertest.cc

Index: content/browser/site_per_process_browsertest.cc
diff --git a/content/browser/site_per_process_browsertest.cc b/content/browser/site_per_process_browsertest.cc
index 8a907d52d7d44a38dfba270d7488ff27cf59572c..3d12dc373ac3f81a4d03f062e58598f6d27857a7 100644
--- a/content/browser/site_per_process_browsertest.cc
+++ b/content/browser/site_per_process_browsertest.cc
@@ -24,6 +24,7 @@
 #include "content/browser/renderer_host/render_widget_host_input_event_router.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/frame_messages.h"
+#include "content/common/view_messages.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
@@ -3514,4 +3515,86 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
   EXPECT_EQ(root, root->frame_tree()->GetFocusedFrame());
 }
 
+class CursorMessageFilter : public content::BrowserMessageFilter {
+ public:
+  explicit CursorMessageFilter()

[dcheng, 2015/10/05 06:48:24]

No explicit.

[kenrb, 2015/10/06 17:39:19]

Done.

+      : content::BrowserMessageFilter(ViewMsgStart),
+        message_loop_runner_(new content::MessageLoopRunner),
+        last_set_cursor_routing_id_(MSG_ROUTING_NONE) {}
+
+  bool OnMessageReceived(const IPC::Message& message) override {
+    if (message.type() == ViewHostMsg_SetCursor::ID) {
+      content::BrowserThread::PostTask(
+          content::BrowserThread::UI, FROM_HERE,
+          base::Bind(&CursorMessageFilter::OnSetCursor, this,
+                     message.routing_id()));
+    }
+    return false;
+  }
+
+  void OnSetCursor(int routing_id) {
+    last_set_cursor_routing_id_ = routing_id;
+    message_loop_runner_->Quit();
+  }
+
+  int last_set_cursor_routing_id() { return last_set_cursor_routing_id_; }

[dcheng, 2015/10/05 06:48:24]

Nit: const.

[kenrb, 2015/10/06 17:39:19]

Done.

+
+  bool Wait() WARN_UNUSED_RESULT {
+    last_set_cursor_routing_id_ = MSG_ROUTING_NONE;
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(

[nasko, 2015/10/05 18:18:46]

Why do we need to post a task at all? If we never get a ViewHostMsg_SetCursor,
then the test should fail, right?

[kenrb, 2015/10/06 17:39:19]

When I tried locally without this, the test ran for a really long time waiting
for the response.

+        FROM_HERE, message_loop_runner_->QuitClosure(),
+        base::TimeDelta::FromMilliseconds(2000));

[dcheng, 2015/10/05 06:48:24]

Is there any significance to 2 seconds?

[kenrb, 2015/10/06 17:39:19]

No, it's arbitrary. Just needed a value large enough that we can be quite
certain if the cursor message hasn't arrived by then, it isn't going to.

+    message_loop_runner_->Run();
+    if (last_set_cursor_routing_id_ == MSG_ROUTING_NONE)
+      return false;
+    return true;
+  }
+
+ private:
+  ~CursorMessageFilter() override {}
+
+  scoped_refptr<content::MessageLoopRunner> message_loop_runner_;
+  int last_set_cursor_routing_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(CursorMessageFilter);
+};
+
+// Verify that we receive a mouse cursor update message when we mouse over
+// a text field contained in an out-of-process iframe.
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
+                       CursorUpdateFromReceivedFromCrossSiteIframe) {
+  GURL main_url(embedded_test_server()->GetURL(
+      "/frame_tree/page_with_positioned_frame.html"));
+  EXPECT_TRUE(NavigateToURL(shell(), main_url));
+
+  FrameTreeNode* root = static_cast<WebContentsImpl*>(shell()->web_contents())
+                            ->GetFrameTree()
+                            ->root();
+
+  FrameTreeNode* child_node = root->child_at(0);
+  EXPECT_NE(shell()->web_contents()->GetSiteInstance(),
+            child_node->current_frame_host()->GetSiteInstance());
+
+  scoped_refptr<CursorMessageFilter> filter = new CursorMessageFilter();
+  child_node->current_frame_host()->GetProcess()->AddFilter(filter.get());
+
+  // Send a MouseMove to the subframe. The frame contains text, and moving the
+  // mouse over it should cause the renderer to send a mouse cursor update.
+  blink::WebMouseEvent mouse_event;
+  mouse_event.type = blink::WebInputEvent::MouseMove;
+  mouse_event.x = 60;
+  mouse_event.y = 60;
+  RenderWidgetHost* rwh_child =
+      root->child_at(0)->current_frame_host()->GetRenderWidgetHost();
+  // rwh_child->ForwardMouseEvent(mouse_event);
+  RenderWidgetHostViewBase* root_view = static_cast<RenderWidgetHostViewBase*>(
+      root->current_frame_host()->GetRenderWidgetHost()->GetView());
+  static_cast<WebContentsImpl*>(shell()->web_contents())
+      ->GetInputEventRouter()
+      ->RouteMouseEvent(root_view, &mouse_event);
+
+  EXPECT_TRUE(filter->Wait());
+  EXPECT_EQ(filter->last_set_cursor_routing_id(), rwh_child->GetRoutingID());
+}
+
 }  // namespace content