Re-land: Implement NativeViewAccessibilityWin using AXPlatformNodeWin.

ui/accessibility/accessibility.gyp

Index: ui/accessibility/accessibility.gyp
diff --git a/ui/accessibility/accessibility.gyp b/ui/accessibility/accessibility.gyp
index ca174fd74f57f35f7555244d75dcbe221080e5aa..88613e68505f8abaa77bcb7c0df1e4cc63e7af7a 100644
--- a/ui/accessibility/accessibility.gyp
+++ b/ui/accessibility/accessibility.gyp
@@ -50,7 +50,16 @@
         'platform/ax_platform_node_delegate.h',
         'platform/ax_platform_node_mac.h',
         'platform/ax_platform_node_mac.mm',
-      ]
+        'platform/ax_platform_node_win.h',
+        'platform/ax_platform_node_win.cc',
+      ],
+      'conditions': [
+        ['OS=="win"', {
+          'dependencies': [
+            '../../third_party/iaccessible2/iaccessible2.gyp:iaccessible2'
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'accessibility_test_support',
@@ -60,8 +69,10 @@
         'accessibility'
       ],
       'sources': [
+        'platform/test_ax_node_wrapper.cc',
+        'platform/test_ax_node_wrapper.h',
         'tree_generator.cc',
-        'tree_generator.h'
+        'tree_generator.h',
       ]
     },
     {
@@ -82,7 +93,15 @@
         'ax_text_utils_unittest.cc',
         'ax_tree_serializer_unittest.cc',
         'ax_tree_unittest.cc',
-      ]
+	'platform/ax_platform_node_win_unittest.cc'
+      ],
+      'conditions': [
+        ['OS=="win"', {
+          'dependencies': [
+            '../../third_party/iaccessible2/iaccessible2.gyp:iaccessible2'
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'ax_gen',