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

content/browser/accessibility/browser_accessibility_cocoa.mm

Index: content/browser/accessibility/browser_accessibility_cocoa.mm
diff --git a/content/browser/accessibility/browser_accessibility_cocoa.mm b/content/browser/accessibility/browser_accessibility_cocoa.mm
index f26fea7f6ac4217bcdb87d8faef7375b155c1045..617f95a3f884592ccbb9866180124d27d68a89c7 100644
--- a/content/browser/accessibility/browser_accessibility_cocoa.mm
+++ b/content/browser/accessibility/browser_accessibility_cocoa.mm
@@ -64,6 +64,9 @@ RoleMap BuildRoleMap() {
     { AccessibilityNodeData::ROLE_BUSY_INDICATOR,
         NSAccessibilityBusyIndicatorRole },
     { AccessibilityNodeData::ROLE_BUTTON, NSAccessibilityButtonRole },
+    { AccessibilityNodeData::ROLE_CANVAS, NSAccessibilityImageRole },
+    { AccessibilityNodeData::ROLE_CANVAS_WITH_FALLBACK_CONTENT,
+        NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_CELL, @"AXCell" },
     { AccessibilityNodeData::ROLE_CHECKBOX, NSAccessibilityCheckBoxRole },
     { AccessibilityNodeData::ROLE_COLOR_WELL, NSAccessibilityColorWellRole },
@@ -81,16 +84,19 @@ RoleMap BuildRoleMap() {
     { AccessibilityNodeData::ROLE_DRAWER, NSAccessibilityDrawerRole },
     { AccessibilityNodeData::ROLE_EDITABLE_TEXT, NSAccessibilityTextFieldRole },
     { AccessibilityNodeData::ROLE_FOOTER, NSAccessibilityGroupRole },
+    { AccessibilityNodeData::ROLE_FORM, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_GRID, NSAccessibilityGridRole },
     { AccessibilityNodeData::ROLE_GROUP, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_GROW_AREA, NSAccessibilityGrowAreaRole },
     { AccessibilityNodeData::ROLE_HEADING, @"AXHeading" },
     { AccessibilityNodeData::ROLE_HELP_TAG, NSAccessibilityHelpTagRole },
+    { AccessibilityNodeData::ROLE_HORIZONTAL_RULE, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_IGNORED, NSAccessibilityUnknownRole },
     { AccessibilityNodeData::ROLE_IMAGE, NSAccessibilityImageRole },
     { AccessibilityNodeData::ROLE_IMAGE_MAP, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_IMAGE_MAP_LINK, NSAccessibilityLinkRole },
     { AccessibilityNodeData::ROLE_INCREMENTOR, NSAccessibilityIncrementorRole },
+    { AccessibilityNodeData::ROLE_LABEL, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_LANDMARK_APPLICATION,
         NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_LANDMARK_BANNER, NSAccessibilityGroupRole },
@@ -120,8 +126,10 @@ RoleMap BuildRoleMap() {
     { AccessibilityNodeData::ROLE_MENU_LIST_POPUP, NSAccessibilityUnknownRole },
     { AccessibilityNodeData::ROLE_NOTE, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_OUTLINE, NSAccessibilityOutlineRole },
+    { AccessibilityNodeData::ROLE_PARAGRAPH, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_POPUP_BUTTON,
         NSAccessibilityPopUpButtonRole },
+    { AccessibilityNodeData::ROLE_PRESENTATIONAL, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_PROGRESS_INDICATOR,
         NSAccessibilityProgressIndicatorRole },
     { AccessibilityNodeData::ROLE_RADIO_BUTTON,
@@ -141,6 +149,7 @@ RoleMap BuildRoleMap() {
     { AccessibilityNodeData::ROLE_SHEET, NSAccessibilitySheetRole },
     { AccessibilityNodeData::ROLE_SLIDER, NSAccessibilitySliderRole },
     { AccessibilityNodeData::ROLE_SLIDER_THUMB, NSAccessibilityGroupRole },
+    { AccessibilityNodeData::ROLE_SPIN_BUTTON, NSAccessibilityTextFieldRole },
     { AccessibilityNodeData::ROLE_SPLITTER, NSAccessibilitySplitterRole },
     { AccessibilityNodeData::ROLE_SPLIT_GROUP, NSAccessibilitySplitGroupRole },
     { AccessibilityNodeData::ROLE_STATIC_TEXT, NSAccessibilityStaticTextRole },
@@ -157,6 +166,7 @@ RoleMap BuildRoleMap() {
     { AccessibilityNodeData::ROLE_TEXTAREA, NSAccessibilityTextAreaRole },
     { AccessibilityNodeData::ROLE_TEXT_FIELD, NSAccessibilityTextFieldRole },
     { AccessibilityNodeData::ROLE_TIMER, NSAccessibilityGroupRole },
+    { AccessibilityNodeData::ROLE_TOGGLE_BUTTON, NSAccessibilityButtonRole },
     { AccessibilityNodeData::ROLE_TOOLBAR, NSAccessibilityToolbarRole },
     { AccessibilityNodeData::ROLE_TOOLTIP, NSAccessibilityGroupRole },
     { AccessibilityNodeData::ROLE_TREE, NSAccessibilityOutlineRole },