Generalize the HIT_TEST accessibility action so that it can send any event.

content/common/accessibility_messages.h

 // 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.
 
 // IPC messages for accessibility.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/ax_content_node_data.h"
 #include "content/common/content_export.h"
 #include "content/common/view_message_enums.h"
@@ skipping 21 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(action)
   IPC_STRUCT_TRAITS_MEMBER(target_node_id)
   IPC_STRUCT_TRAITS_MEMBER(flags)
   IPC_STRUCT_TRAITS_MEMBER(anchor_node_id)
   IPC_STRUCT_TRAITS_MEMBER(anchor_offset)
   IPC_STRUCT_TRAITS_MEMBER(focus_node_id)
   IPC_STRUCT_TRAITS_MEMBER(focus_offset)
   IPC_STRUCT_TRAITS_MEMBER(target_rect)
   IPC_STRUCT_TRAITS_MEMBER(target_point)
   IPC_STRUCT_TRAITS_MEMBER(value)
+  IPC_STRUCT_TRAITS_MEMBER(hit_test_event_to_fire)
 IPC_STRUCT_TRAITS_END()
 
 IPC_STRUCT_TRAITS_BEGIN(content::AXContentNodeData)
   IPC_STRUCT_TRAITS_MEMBER(id)
   IPC_STRUCT_TRAITS_MEMBER(role)
   IPC_STRUCT_TRAITS_MEMBER(state)
   IPC_STRUCT_TRAITS_MEMBER(location)
   IPC_STRUCT_TRAITS_MEMBER(transform)
   IPC_STRUCT_TRAITS_MEMBER(string_attributes)
   IPC_STRUCT_TRAITS_MEMBER(int_attributes)
@@ skipping 83 matching lines @@
 // such as focusing or clicking on a node.
 IPC_MESSAGE_ROUTED1(AccessibilityMsg_PerformAction,
                     ui::AXActionData  /* action parameters */)
 
 // Determine the accessibility object under a given point.
 //
 // If the target is an object with a child frame (like if the hit test
 // result is an iframe element), it responds with
 // AccessibilityHostMsg_ChildFrameHitTestResult so that the
 // hit test can be performed recursively on the child frame. Otherwise
-// it fires an accessibility event of type ui::AX_EVENT_HOVER on the target.
-IPC_MESSAGE_ROUTED1(AccessibilityMsg_HitTest,
-                    gfx::Point /* location to test */)
+// it fires an accessibility event of type |event_to_fire| on the target.
+IPC_MESSAGE_ROUTED2(AccessibilityMsg_HitTest,
+                    gfx::Point /* location to test */,
+                    ui::AXEvent /* event to fire */)
 
 // Relay a request from assistive technology to set accessibility focus
 // to a given node. On platforms where this is used (currently Android),
 // inline text boxes are only computed for the node with accessibility focus,
 // rather than for the whole tree.
 IPC_MESSAGE_ROUTED1(AccessibilityMsg_SetAccessibilityFocus,
                     int /* object id */)
 
 // Tells the render view that a AccessibilityHostMsg_Events
 // message was processed and it can send additional events. The argument
@@ skipping 40 matching lines @@
 IPC_MESSAGE_ROUTED1(
     AccessibilityHostMsg_LocationChanges,
     std::vector<AccessibilityHostMsg_LocationChangeParams>)
 
 // Sent to update the browser of Find In Page results.
 IPC_MESSAGE_ROUTED1(
     AccessibilityHostMsg_FindInPageResult,
     AccessibilityHostMsg_FindInPageResultParams)
 
 // Sent in response to AccessibilityMsg_HitTest.
-IPC_MESSAGE_ROUTED2(AccessibilityHostMsg_ChildFrameHitTestResult,
+IPC_MESSAGE_ROUTED3(AccessibilityHostMsg_ChildFrameHitTestResult,
                     gfx::Point /* location tested */,
-                    int /* node id of result */)
+                    int /* node id of result */,
+                    ui::AXEvent /* event to fire */)
 
 // Sent in response to AccessibilityMsg_SnapshotTree. The callback id that was
 // passed to the request will be returned in |callback_id|, along with
 // a standalone snapshot of the accessibility tree.
 IPC_MESSAGE_ROUTED2(AccessibilityHostMsg_SnapshotResponse,
                     int /* callback_id */,
                     content::AXContentTreeUpdate)