Cross-process iframe accessibility.

content/browser/accessibility/browser_accessibility_manager.h

Index: content/browser/accessibility/browser_accessibility_manager.h
diff --git a/content/browser/accessibility/browser_accessibility_manager.h b/content/browser/accessibility/browser_accessibility_manager.h
index c3f0430935fc958d8f524da16efe5bc90d517c07..bfbc68adca8194bed97dc90bac727a03e978e346 100644
--- a/content/browser/accessibility/browser_accessibility_manager.h
+++ b/content/browser/accessibility/browser_accessibility_manager.h
@@ -13,7 +13,7 @@
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/web/WebAXEnums.h"
 #include "ui/accessibility/ax_node_data.h"
-#include "ui/accessibility/ax_tree.h"
+#include "ui/accessibility/ax_serializable_tree.h"
 #include "ui/accessibility/ax_tree_update.h"
 #include "ui/gfx/native_widget_types.h"
 
@@ -22,6 +22,7 @@ struct AccessibilityHostMsg_LocationChangeParams;
 
 namespace content {
 class BrowserAccessibility;
+class BrowserAccessibilityManager;
 #if defined(OS_ANDROID)
 class BrowserAccessibilityManagerAndroid;
 #endif
@@ -29,6 +30,8 @@ class BrowserAccessibilityManagerAndroid;
 class BrowserAccessibilityManagerWin;
 #endif
 
+const int kNoFrameId = -1;

[Charlie Reis, 2014/08/21 19:23:27]

This is a bit ambiguous for a content-wide constant.  Beyond clarifying frame
routing ID vs FrameTreeNode ID vs node ID, we should probably add "Ax" in the
name.

[dmazzoni, 2014/08/25 06:49:36]

WIth the other changes, this is only needed in browser_accessibility.cc now.
Frame tree node ids start at 1, so maybe we don't need a constant at all? I can
just document that it's only valid if nonzero.

+
 // For testing.
 CONTENT_EXPORT ui::AXTreeUpdate MakeAXTreeUpdate(
     const ui::AXNodeData& node,
@@ -63,6 +66,9 @@ class CONTENT_EXPORT BrowserAccessibilityDelegate {
   virtual void AccessibilityFatalError() = 0;
   virtual gfx::AcceleratedWidget AccessibilityGetAcceleratedWidget() = 0;
   virtual gfx::NativeViewAccessible AccessibilityGetNativeViewAccessible() = 0;
+  virtual BrowserAccessibilityManager* AccessibilityGetChildFrame(
+      int64 frame_id) = 0;
+  virtual BrowserAccessibilityManager* AccessibilityGetParentFrame() = 0;
 };
 
 class CONTENT_EXPORT BrowserAccessibilityFactory {
@@ -189,6 +195,14 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
     delegate_ = delegate;
   }
 
+  // Get a snapshot of the current tree as an AXTreeUpdate.
+  ui::AXTreeUpdate SnapshotAXTreeForTesting();
+
+  // Frame tree support.
+  void SetNodeIdInParentFrame(int32 node_id);
+  void SetChildFrameId(int32 node_id, int64 child_frame_id);
+  BrowserAccessibility* GetCrossFrameParent();
+
  protected:
   BrowserAccessibilityManager(
       BrowserAccessibilityDelegate* delegate,
@@ -225,21 +239,6 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
     OSK_ALLOWED
   };
 
-  // Update a set of nodes using data received from the renderer
-  // process.
-  bool UpdateNodes(const std::vector<ui::AXNodeData>& nodes);
-
-  // Update one node from the tree using data received from the renderer
-  // process. Returns true on success, false on fatal error.
-  bool UpdateNode(const ui::AXNodeData& src);
-
-  void SetRoot(BrowserAccessibility* root);
-
-  BrowserAccessibility* CreateNode(
-      BrowserAccessibility* parent,
-      int32 id,
-      int32 index_in_parent);
-
  protected:
   // The object that can perform actions on our behalf.
   BrowserAccessibilityDelegate* delegate_;
@@ -248,7 +247,7 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
   scoped_ptr<BrowserAccessibilityFactory> factory_;
 
   // The underlying tree of accessibility objects.
-  scoped_ptr<ui::AXTree> tree_;
+  scoped_ptr<ui::AXSerializableTree> tree_;
 
   // The node that currently has focus.
   ui::AXNode* focus_;
@@ -256,6 +255,11 @@ class CONTENT_EXPORT BrowserAccessibilityManager : public ui::AXTreeDelegate {
   // A mapping from a node id to its wrapper of type BrowserAccessibility.
   base::hash_map<int32, BrowserAccessibility*> id_wrapper_map_;
 
+  // This is set if this tree's frame is the child of another frame.
+  // It's the id of the node in the parent frame that's the parent of this
+  // frame's root object.

[Charlie Reis, 2014/08/20 20:37:13]

This comment is kind of hard to follow.  Maybe it would be clearer with an
example?

[dmazzoni, 2014/08/20 20:57:17]

Sure.

I'll work on the comment, but for purposes of your understanding the code
review:

Imagine frame P has an iframe element with node id 37, where that id is relative
to its frame.

The iframe's accessibility tree is this BrowserAccessibilityManager. This field
tells us the id - 37 - of the element that hosts this whole frame in the parent
frame.

This is needed so we can walk back up the tree. If the client requests the
parent of the root of this tree, we need to return the object id=37 from the
parent frame.

[dmazzoni, 2014/08/25 06:49:36]

This is gone now.

+  uint32 node_id_in_parent_frame_;
+
   // The on-screen keyboard state.
   OnScreenKeyboardState osk_state_;