Cross-process iframe accessibility.

content/browser/renderer_host/render_view_host_impl.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/renderer_host/render_view_host_impl.h"
 
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
 #include "base/json/json_reader.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/sys_info.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "cc/base/switches.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
+#include "content/browser/accessibility/frame_tree_accessibility.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/cross_site_request_manager.h"
 #include "content/browser/dom_storage/session_storage_namespace_impl.h"
+#include "content/browser/frame_host/cross_process_frame_connector.h"
 #include "content/browser/frame_host/frame_tree.h"
+#include "content/browser/frame_host/render_widget_host_view_child_frame.h"
 #include "content/browser/gpu/compositor_util.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/gpu/gpu_process_host.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/browser/host_zoom_map_impl.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
 #include "content/browser/renderer_host/dip_util.h"
 #include "content/browser/renderer_host/input/timeout_monitor.h"
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
@@ skipping 194 matching lines @@
                    base::Unretained(ResourceDispatcherHostImpl::Get()),
                    GetProcess()->GetID(), GetRoutingID()));
   }
 
 #if defined(OS_ANDROID)
   media_player_manager_.reset(BrowserMediaPlayerManager::Create(this));
 #endif
 
   unload_event_monitor_timeout_.reset(new TimeoutMonitor(base::Bind(
       &RenderViewHostImpl::OnSwappedOut, weak_factory_.GetWeakPtr(), true)));
+
+  FrameTreeAccessibility::GetInstance()->OnFrameCreated(this);
 }
 
 RenderViewHostImpl::~RenderViewHostImpl() {
   if (ResourceDispatcherHostImpl::Get()) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&ResourceDispatcherHostImpl::OnRenderViewHostDeleted,
                    base::Unretained(ResourceDispatcherHostImpl::Get()),
                    GetProcess()->GetID(), GetRoutingID()));
   }
 
   delegate_->RenderViewDeleted(this);
 
   // Be sure to clean up any leftover state from cross-site requests.
   CrossSiteRequestManager::GetInstance()->SetHasPendingCrossSiteRequest(
       GetProcess()->GetID(), GetRoutingID(), false);
 
   // If this was swapped out, it already decremented the active view
   // count of the SiteInstance it belongs to.
   if (IsRVHStateActive(rvh_state_))
     instance_->decrement_active_view_count();
+
+  FrameTreeAccessibility::GetInstance()->OnFrameDeleted(this);
 }
 
 RenderViewHostDelegate* RenderViewHostImpl::GetDelegate() const {
   return delegate_;
 }
 
 SiteInstance* RenderViewHostImpl::GetSiteInstance() const {
   return instance_.get();
 }
 
@@ skipping 1318 matching lines @@
 
 void RenderViewHostImpl::ExecutePluginActionAtLocation(
   const gfx::Point& location, const blink::WebPluginAction& action) {
   Send(new ViewMsg_PluginActionAt(GetRoutingID(), location, action));
 }
 
 void RenderViewHostImpl::NotifyMoveOrResizeStarted() {
   Send(new ViewMsg_MoveOrResizeStarted(GetRoutingID()));
 }
 
+static int GetAccessibleFrameId(int process_id, int frame_routing_id) {
+  RenderFrameHostImpl* render_frame_host = RenderFrameHostImpl::FromID(
+      process_id, frame_routing_id);
+  if (render_frame_host) {
+    CrossProcessFrameConnector* connector =
+        render_frame_host->cross_process_frame_connector();
+    if (connector) {
+      RenderWidgetHostViewChildFrame* view = connector->view();
+      if (view) {
+        RenderWidgetHostImpl* rwhi =
+            RenderWidgetHostImpl::From(view->GetRenderWidgetHost());
+        return FrameTreeAccessibility::GetInstance()->GetFrameId(rwhi);
+      }
+    }
+  }
+
+  return 0;
+}
+
 void RenderViewHostImpl::OnAccessibilityEvents(
     const std::vector<AccessibilityHostMsg_EventParams>& params) {
+  BrowserAccessibilityManager* manager = NULL;
   if ((accessibility_mode() != AccessibilityModeOff) && view_ &&
       IsRVHStateActive(rvh_state_)) {
+    // Send the updates to the BrowserAccessibilityManager to support
+    // native accessibility APIs.
     if (accessibility_mode() & AccessibilityModeFlagPlatform) {
       view_->CreateBrowserAccessibilityManagerIfNeeded();
-      BrowserAccessibilityManager* manager =
-          view_->GetBrowserAccessibilityManager();
-      if (manager)
+      manager = view_->GetBrowserAccessibilityManager();
+      if (manager) {
         manager->OnAccessibilityEvents(params);
+        FrameTreeAccessibility::GetInstance()->SetFrameAccessibilityManager(
+            this, manager);
+      }
     }
 
+    // Map from guest instance ids (for a <webview> plug-in) and
+    // frame routing ids (from out-of-process iframes) to accessibility
+    // frame ids.
+    std::map<int32, int>::const_iterator iter;
+    for (unsigned int i = 0; i < params.size(); ++i) {
+      const AccessibilityHostMsg_EventParams& param = params[i];
+      for (iter = param.frame_routing_ids.begin();
+           iter != param.frame_routing_ids.end();

[ncarter (slow), 2014/05/02 19:10:02]

Nothing happens with param.guest_instance_ids here, though the comment suggests
ambition otherwise.

+           ++iter) {
+        int32 node_id = iter->first;
+        int frame_routing_id = iter->second;
+        int accessible_frame_id = GetAccessibleFrameId(
+            GetProcess()->GetID(), frame_routing_id);
+        if (manager && accessible_frame_id)
+          manager->SetChildFrameId(node_id, accessible_frame_id);
+      }
+    }
+
+    // Send the updates to the automation extension API.
     std::vector<AXEventNotificationDetails> details;
     for (unsigned int i = 0; i < params.size(); ++i) {
       const AccessibilityHostMsg_EventParams& param = params[i];
       AXEventNotificationDetails detail(param.update.nodes,
                                         param.event_type,
                                         param.id,
                                         GetProcess()->GetID(),
                                         GetRoutingID());
       details.push_back(detail);
     }
-
     delegate_->AccessibilityEventReceived(details);
   }
 
   // Always send an ACK or the renderer can be in a bad state.
   Send(new AccessibilityMsg_Events_ACK(GetRoutingID()));
 
   // The rest of this code is just for testing; bail out if we're not
   // in that mode.
   if (accessibility_testing_callback_.is_null())
     return;
 
   for (unsigned i = 0; i < params.size(); i++) {
     const AccessibilityHostMsg_EventParams& param = params[i];
     if (static_cast<int>(param.event_type) < 0)
       continue;
-    if (!ax_tree_)
-      ax_tree_.reset(new ui::AXTree(param.update));
-    else
+    if (!ax_tree_) {
+      if (manager) {
+        ax_tree_.reset(new ui::AXTree(manager->SnapshotAXTreeForTesting()));

[ncarter (slow), 2014/05/02 19:10:02]

What prevents this ForTesting() path from becoming active in production chrome?

+      } else {
+        ax_tree_.reset(new ui::AXTree());
+        CHECK(ax_tree_->Unserialize(param.update)) << ax_tree_->error();
+      }
+    } else {
       CHECK(ax_tree_->Unserialize(param.update)) << ax_tree_->error();
+    }
     accessibility_testing_callback_.Run(param.event_type);
   }
 }
 
 void RenderViewHostImpl::OnAccessibilityLocationChanges(
     const std::vector<AccessibilityHostMsg_LocationChangeParams>& params) {
   if (view_ && IsRVHStateActive(rvh_state_)) {
     if (accessibility_mode() & AccessibilityModeFlagPlatform) {
       view_->CreateBrowserAccessibilityManagerIfNeeded();
       BrowserAccessibilityManager* manager =
@@ skipping 91 matching lines @@
   return true;
 }
 
 void RenderViewHostImpl::AttachToFrameTree() {
   FrameTree* frame_tree = delegate_->GetFrameTree();
 
   frame_tree->ResetForMainFrameSwap();
 }
 
 }  // namespace content