Removing unused roles(7) from blink.

Source/modules/accessibility/AXObject.h

Index: Source/modules/accessibility/AXObject.h
diff --git a/Source/modules/accessibility/AXObject.h b/Source/modules/accessibility/AXObject.h
index 619a667e6e953205d97516dfa6950ce8c9d90a8a..ab5e9fb4dd10b971fdf7e01bdaff5b2af9009f6d 100644
--- a/Source/modules/accessibility/AXObject.h
+++ b/Source/modules/accessibility/AXObject.h
@@ -59,7 +59,6 @@ enum AccessibilityRole {
     ArticleRole,
     BannerRole,
     BlockquoteRole,
-    BrowserRole,
     BusyIndicatorRole,
     ButtonRole,
     CanvasRole,
@@ -83,7 +82,6 @@ enum AccessibilityRole {
     DisclosureTriangleRole,
     DivRole,
     DocumentRole,
-    DrawerRole,
     EditableTextRole,
     EmbeddedObjectRole,
     FigcaptionRole,
@@ -94,7 +92,6 @@ enum AccessibilityRole {
     GroupRole,
     GrowAreaRole,
     HeadingRole,
-    HelpTagRole,
     IframeRole,
     IgnoredRole,
     ImageMapLinkRole,
@@ -114,7 +111,6 @@ enum AccessibilityRole {
     MarqueeRole,
     MathElementRole,
     MathRole,
-    MatteRole,
     MenuBarRole,
     MenuButtonRole,
     MenuItemRole,
@@ -140,14 +136,12 @@ enum AccessibilityRole {
     RowHeaderRole,
     RowRole,
     RubyRole,
-    RulerMarkerRole,
     RulerRole,
     SVGRootRole,
     ScrollAreaRole,
     ScrollBarRole,
     SeamlessWebAreaRole,
     SearchRole,
-    SheetRole,
     SliderRole,
     SliderThumbRole,
     SpinButtonPartRole,
@@ -156,7 +150,6 @@ enum AccessibilityRole {
     SplitterRole,
     StaticTextRole,
     StatusRole,
-    SystemWideRole,
     TabGroupRole,
     TabListRole,
     TabPanelRole,
@@ -174,7 +167,6 @@ enum AccessibilityRole {
     TreeRole,
     UnknownRole,
     UserInterfaceTooltipRole,
-    ValueIndicatorRole,
     WebAreaRole,
     WindowRole,
 };