Add support for new accessibility roles from WebKit, with tests.

content/common/accessibility_node_data.h

Index: content/common/accessibility_node_data.h
diff --git a/content/common/accessibility_node_data.h b/content/common/accessibility_node_data.h
index 640df553a763fe1db58248b5278e99469d5aeb36..bab81e39de657caafacb339a9ff90d151de8ab2d 100644
--- a/content/common/accessibility_node_data.h
+++ b/content/common/accessibility_node_data.h
@@ -37,6 +37,8 @@ struct CONTENT_EXPORT AccessibilityNodeData {
     ROLE_BROWSER,
     ROLE_BUSY_INDICATOR,
     ROLE_BUTTON,
+    ROLE_CANVAS,
+    ROLE_CANVAS_WITH_FALLBACK_CONTENT,
     ROLE_CELL,
     ROLE_CHECKBOX,
     ROLE_COLOR_WELL,
@@ -48,20 +50,24 @@ struct CONTENT_EXPORT AccessibilityNodeData {
     ROLE_DIALOG,
     ROLE_DIRECTORY,
     ROLE_DISCLOSURE_TRIANGLE,
+    ROLE_DIV,
     ROLE_DOCUMENT,
     ROLE_DRAWER,
     ROLE_EDITABLE_TEXT,
     ROLE_FOOTER,
+    ROLE_FORM,
     ROLE_GRID,
     ROLE_GROUP,
     ROLE_GROW_AREA,
     ROLE_HEADING,
     ROLE_HELP_TAG,
+    ROLE_HORIZONTAL_RULE,
     ROLE_IGNORED,
     ROLE_IMAGE,
     ROLE_IMAGE_MAP,
     ROLE_IMAGE_MAP_LINK,
     ROLE_INCREMENTOR,
+    ROLE_LABEL,
     ROLE_LANDMARK_APPLICATION,
     ROLE_LANDMARK_BANNER,
     ROLE_LANDMARK_COMPLEMENTARY,
@@ -87,7 +93,9 @@ struct CONTENT_EXPORT AccessibilityNodeData {
     ROLE_MENU_LIST_POPUP,
     ROLE_NOTE,
     ROLE_OUTLINE,
+    ROLE_PARAGRAPH,
     ROLE_POPUP_BUTTON,
+    ROLE_PRESENTATIONAL,
     ROLE_PROGRESS_INDICATOR,
     ROLE_RADIO_BUTTON,
     ROLE_RADIO_GROUP,
@@ -101,6 +109,8 @@ struct CONTENT_EXPORT AccessibilityNodeData {
     ROLE_SHEET,
     ROLE_SLIDER,
     ROLE_SLIDER_THUMB,
+    ROLE_SPIN_BUTTON,
+    ROLE_SPIN_BUTTON_PART,
     ROLE_SPLITTER,
     ROLE_SPLIT_GROUP,
     ROLE_STATIC_TEXT,
@@ -115,6 +125,7 @@ struct CONTENT_EXPORT AccessibilityNodeData {
     ROLE_TEXTAREA,
     ROLE_TEXT_FIELD,
     ROLE_TIMER,
+    ROLE_TOGGLE_BUTTON,
     ROLE_TOOLBAR,
     ROLE_TOOLTIP,
     ROLE_TREE,