Add a WebContentsImpl API to snapshot the accessibility tree.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 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/frame_host/render_frame_host_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
@@ skipping 46 matching lines @@
 #include "content/public/browser/permission_type.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/stream_handle.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/common/url_utils.h"
 #include "ui/accessibility/ax_tree.h"
+#include "ui/accessibility/ax_tree_update.h"
 #include "url/gurl.h"
 
 #if defined(OS_MACOSX)
 #include "content/browser/frame_host/popup_menu_helper_mac.h"
 #endif
 
 #if defined(ENABLE_MEDIA_MOJO_RENDERER)
 #include "media/mojo/interfaces/media_renderer.mojom.h"
 #include "media/mojo/services/mojo_renderer_service.h"
 #endif
@@ skipping 297 matching lines @@
     IPC_MESSAGE_HANDLER(FrameHostMsg_BeginNavigation,
                         OnBeginNavigation)
     IPC_MESSAGE_HANDLER(FrameHostMsg_DispatchLoad, OnDispatchLoad)
     IPC_MESSAGE_HANDLER(FrameHostMsg_TextSurroundingSelectionResponse,
                         OnTextSurroundingSelectionResponse)
     IPC_MESSAGE_HANDLER(AccessibilityHostMsg_Events, OnAccessibilityEvents)
     IPC_MESSAGE_HANDLER(AccessibilityHostMsg_LocationChanges,
                         OnAccessibilityLocationChanges)
     IPC_MESSAGE_HANDLER(AccessibilityHostMsg_FindInPageResult,
                         OnAccessibilityFindInPageResult)
+    IPC_MESSAGE_HANDLER(AccessibilityHostMsg_SnapshotResponse,
+                        OnAccessibilitySnapshotResponse)
     IPC_MESSAGE_HANDLER(FrameHostMsg_ToggleFullscreen, OnToggleFullscreen)
     // The following message is synthetic and doesn't come from RenderFrame, but
     // from RenderProcessHost.
     IPC_MESSAGE_HANDLER(FrameHostMsg_RenderProcessGone, OnRenderProcessGone)
 #if defined(OS_MACOSX) || defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(FrameHostMsg_ShowPopup, OnShowPopup)
     IPC_MESSAGE_HANDLER(FrameHostMsg_HidePopup, OnHidePopup)
 #endif
   IPC_END_MESSAGE_MAP()
 
@@ skipping 991 matching lines @@
     BrowserAccessibilityManager* manager =
         GetOrCreateBrowserAccessibilityManager();
     if (manager) {
       manager->OnFindInPageResult(
           params.request_id, params.match_index, params.start_id,
           params.start_offset, params.end_id, params.end_offset);
     }
   }
 }
 
+void RenderFrameHostImpl::OnAccessibilitySnapshotResponse(
+    int token,
+    const ui::AXTreeUpdate& snapshot) {
+  std::map<int, AXTreeSnapshotCallback>::iterator it =
+      ax_tree_snapshot_callbacks_.find(token);
+  if (it != ax_tree_snapshot_callbacks_.end()) {
+    it->second.Run(snapshot);
+    ax_tree_snapshot_callbacks_.erase(it);
+  } else {
+    NOTREACHED() << "Received AX tree snapshot response for unknown request";
+  }
+}
+
 void RenderFrameHostImpl::OnToggleFullscreen(bool enter_fullscreen) {
   if (enter_fullscreen)
     delegate_->EnterFullscreenMode(GetLastCommittedURL().GetOrigin());
   else
     delegate_->ExitFullscreenMode();
 
   // The previous call might change the fullscreen state. We need to make sure
   // the renderer is aware of that, which is done via the resize message.
   render_view_host_->WasResized();
 }
@@ skipping 393 matching lines @@
   // As a sanity check, make sure the frame belongs to the same BrowserContext.
   CHECK_EQ(GetSiteInstance()->GetBrowserContext(),
            other_render_frame_host->GetSiteInstance()->GetBrowserContext());
   return GetSiteInstance() == other_render_frame_host->GetSiteInstance();
 }
 
 void RenderFrameHostImpl::SetAccessibilityMode(AccessibilityMode mode) {
   Send(new FrameMsg_SetAccessibilityMode(routing_id_, mode));
 }
 
+void RenderFrameHostImpl::RequestAXTreeSnapshot(
+    AXTreeSnapshotCallback callback) {
+  static int next_token = 1;
+  int token = next_token++;
+  Send(new AccessibilityMsg_SnapshotTree(routing_id_, token));
+  ax_tree_snapshot_callbacks_.insert(std::make_pair(token, callback));
+}
+
 void RenderFrameHostImpl::SetAccessibilityCallbackForTesting(
     const base::Callback<void(ui::AXEvent, int)>& callback) {
   accessibility_testing_callback_ = callback;
 }
 
 const ui::AXTree* RenderFrameHostImpl::GetAXTreeForTesting() {
   return ax_tree_for_testing_.get();
 }
 
 BrowserAccessibilityManager*
@@ skipping 131 matching lines @@
     return;
 
   permission_manager->RegisterPermissionUsage(
       PermissionType::GEOLOCATION,
       GetLastCommittedURL().GetOrigin(),
       frame_tree_node()->frame_tree()->GetMainFrame()
           ->GetLastCommittedURL().GetOrigin());
 }
 
 }  // namespace content