Make load events in iframe elements work with OOPIF (Chromium side).

Today, when the parent frame defines a load event handler in the
iframe element of an out-of-process child frame, the event does not
fire in the parent process.  This CL adds the plumbing to forward the
event from the child frame's process to the parent frame's process.

Blink side: https://codereview.chromium.org/937203003

BUG=453690

Review URL: https://codereview.chromium.org/954793002

Cr-Commit-Position: refs/heads/master@{#318101}

content/browser/frame_host/render_frame_host_impl.cc

@@ -373,6 +373,7 @@ bool RenderFrameHostImpl::OnMessageReceived(const IPC::Message &msg) {
     IPC_MESSAGE_HANDLER(FrameHostMsg_UpdateEncoding, OnUpdateEncoding)
     IPC_MESSAGE_HANDLER(FrameHostMsg_BeginNavigation,
                         OnBeginNavigation)
+    IPC_MESSAGE_HANDLER(FrameHostMsg_DispatchLoad, OnDispatchLoad)
     IPC_MESSAGE_HANDLER(FrameHostMsg_TextSurroundingSelectionResponse,
                         OnTextSurroundingSelectionResponse)
     IPC_MESSAGE_HANDLER(AccessibilityHostMsg_Events, OnAccessibilityEvents)
@@ -1223,6 +1224,21 @@ void RenderFrameHostImpl::OnBeginNavigation(
       frame_tree_node(), common_params, begin_params, body);
 }
 
+void RenderFrameHostImpl::OnDispatchLoad() {
+  CHECK(base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kSitePerProcess));
+  // Only frames with an out-of-process parent frame should be sending this
+  // message.
+  RenderFrameProxyHost* proxy =
+      frame_tree_node()->render_manager()->GetProxyToParent();
+  if (!proxy) {
+    GetProcess()->ReceivedBadMessage();
+    return;
+  }
+
+  proxy->Send(new FrameMsg_DispatchLoad(proxy->GetRoutingID()));
+}
+
 void RenderFrameHostImpl::OnAccessibilityEvents(
     const std::vector<AccessibilityHostMsg_EventParams>& params,
     int reset_token) {

content/browser/frame_host/render_frame_host_impl.h

@@ -501,6 +501,7 @@ class CONTENT_EXPORT RenderFrameHostImpl
   void OnBeginNavigation(const CommonNavigationParams& common_params,
                          const BeginNavigationParams& begin_params,
                          scoped_refptr<ResourceRequestBody> body);
+  void OnDispatchLoad();
   void OnAccessibilityEvents(
       const std::vector<AccessibilityHostMsg_EventParams>& params,
       int reset_token);

content/browser/site_per_process_browsertest.cc

@@ -1353,4 +1353,38 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest,
   EXPECT_TRUE(node3->current_frame_host()->IsRenderFrameLive());
 }
 
+// Verify that load events for iframe elements work when the child frame is
+// out-of-process.  In such cases, the load event is forwarded from the child
+// frame to the parent frame via the browser process.
+IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, LoadEventForwarding) {
+  // Load a page with a cross-site frame.  The parent page has an onload
+  // handler in the iframe element that appends "LOADED" to the document title.
+  {
+    GURL main_url(
+        embedded_test_server()->GetURL("/frame_with_load_event.html"));
+    base::string16 expected_title(base::UTF8ToUTF16("LOADED"));
+    TitleWatcher title_watcher(shell()->web_contents(), expected_title);
+    EXPECT_TRUE(NavigateToURL(shell(), main_url));
+    EXPECT_EQ(title_watcher.WaitAndGetTitle(), expected_title);
+  }
+
+  // It is safe to obtain the root frame tree node here, as it doesn't change.
+  FrameTreeNode* root = static_cast<WebContentsImpl*>(shell()->web_contents())
+                            ->GetFrameTree()
+                            ->root();
+
+  // Load another cross-site page into the iframe and check that the load event
+  // is fired.
+  {
+    GURL foo_url(embedded_test_server()->GetURL("foo.com", "/title1.html"));
+    base::string16 expected_title(base::UTF8ToUTF16("LOADEDLOADED"));
+    TitleWatcher title_watcher(shell()->web_contents(), expected_title);
+    TestNavigationObserver observer(shell()->web_contents());
+    NavigateFrameToURL(root->child_at(0), foo_url);
+    EXPECT_TRUE(observer.last_navigation_succeeded());
+    EXPECT_EQ(foo_url, observer.last_navigation_url());
+    EXPECT_EQ(title_watcher.WaitAndGetTitle(), expected_title);
+  }
+}
+
 }  // namespace content

content/common/frame_messages.h

@@ -521,6 +521,9 @@ IPC_MESSAGE_ROUTED1(FrameMsg_AddStyleSheetByURL, std::string)
 IPC_MESSAGE_ROUTED1(FrameMsg_SetAccessibilityMode,
                     AccessibilityMode)
 
+// Dispatch a load event in the iframe element containing this frame.
+IPC_MESSAGE_ROUTED0(FrameMsg_DispatchLoad)
+
 #if defined(OS_ANDROID)
 
 // External popup menus.
@@ -861,6 +864,10 @@ IPC_MESSAGE_ROUTED1(FrameHostMsg_BeforeUnloadHandlersPresent,
 IPC_MESSAGE_ROUTED1(FrameHostMsg_UnloadHandlersPresent,
                     bool /* present */)
 
+// Dispatch a load event for this frame in the iframe element of an
+// out-of-process parent frame.
+IPC_MESSAGE_ROUTED0(FrameHostMsg_DispatchLoad)
+
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
 
 // Message to show/hide a popup menu using native controls.

content/renderer/render_frame_impl.cc

@@ -2768,6 +2768,10 @@ void RenderFrameImpl::didChangeThemeColor() {
       routing_id_, frame_->document().themeColor()));
 }
 
+void RenderFrameImpl::dispatchLoad() {
+  Send(new FrameHostMsg_DispatchLoad(routing_id_));
+}
+
 void RenderFrameImpl::requestNotificationPermission(
     const blink::WebSecurityOrigin& origin,
     blink::WebNotificationPermissionCallback* callback) {

content/renderer/render_frame_impl.h

@@ -423,6 +423,7 @@ class CONTENT_EXPORT RenderFrameImpl
   virtual void addNavigationTransitionData(
       const blink::WebTransitionElementData& data);
   virtual void didChangeThemeColor();
+  virtual void dispatchLoad();
   virtual void requestNotificationPermission(
       const blink::WebSecurityOrigin& origin,
       blink::WebNotificationPermissionCallback* callback);

content/renderer/render_frame_proxy.cc

@@ -185,6 +185,7 @@ bool RenderFrameProxy::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(FrameMsg_DisownOpener, OnDisownOpener)
     IPC_MESSAGE_HANDLER(FrameMsg_DidStartLoading, OnDidStartLoading)
     IPC_MESSAGE_HANDLER(FrameMsg_DidStopLoading, OnDidStopLoading)
+    IPC_MESSAGE_HANDLER(FrameMsg_DispatchLoad, OnDispatchLoad)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -262,6 +263,10 @@ void RenderFrameProxy::OnDidStopLoading() {
   web_frame_->didStopLoading();
 }
 
+void RenderFrameProxy::OnDispatchLoad() {
+  web_frame_->DispatchLoadEventForFrameOwner();
+}
+
 void RenderFrameProxy::frameDetached() {
   if (web_frame_->parent())
     web_frame_->parent()->removeChild(web_frame_);

content/renderer/render_frame_proxy.h

@@ -140,6 +140,7 @@ class CONTENT_EXPORT RenderFrameProxy
   void OnCompositorFrameSwapped(const IPC::Message& message);
   void OnDisownOpener();
   void OnDidStopLoading();
+  void OnDispatchLoad();
 
   // The routing ID by which this RenderFrameProxy is known.
   const int routing_id_;

content/test/data/frame_with_load_event.html

@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+</head>
+<body>
+  This page has a cross-site iframe with a load event.
+  <iframe id='test' onload="document.title += 'LOADED';" src="/cross-site/baz.com/title1.html"></iframe>
+</body>
+</html>
+