Split out the MSCOM pieces of BrowserAccessibilityWin into a seperate class.

ui/accessibility/platform/ax_platform_node_base.h

 // Copyright 2014 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.
 
 #ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_BASE_H_
 #define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_BASE_H_
 
 #include "base/macros.h"
 #include "ui/accessibility/ax_enums.h"
 #include "ui/accessibility/platform/ax_platform_node.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/native_widget_types.h"
 
 namespace ui {
 
 struct AXNodeData;
 class AXPlatformNodeDelegate;
 
-class AXPlatformNodeBase : public AXPlatformNode {
+class AX_EXPORT AXPlatformNodeBase : public AXPlatformNode {
  public:
    virtual void Init(AXPlatformNodeDelegate* delegate);
 
   // These are simple wrappers to our delegate.
   const AXNodeData& GetData() const;
   gfx::Rect GetBoundsInScreen() const;
   gfx::NativeViewAccessible GetParent();
   int GetChildCount();
   gfx::NativeViewAccessible ChildAtIndex(int index);
 
@@ skipping 48 matching lines @@
   // Sets the text selection in this object if possible.
   bool SetTextSelection(int start_offset, int end_offset);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AXPlatformNodeBase);
 };
 
 }  // namespace ui
 
 #endif  // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_BASE_H_