Move some accessibility methods, enums and interfaces into the content/public API.

content/browser/accessibility/dump_accessibility_tree_helper_mac.mm

Index: content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
diff --git a/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm b/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
index 669956b63bf7e168de21b1c8e05b45b79f383cd8..5584cd44c0f47a40c5395dd81317ca797e3b13f6 100644
--- a/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
+++ b/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
@@ -112,27 +112,30 @@ string16 DumpAccessibilityTreeHelper::ToString(BrowserAccessibility* node,
   return ASCIIToUTF16(prefix) + FinishLine() + ASCIIToUTF16("\n");
 }
 
+// static
 const base::FilePath::StringType
-DumpAccessibilityTreeHelper::GetActualFileSuffix()
-    const {
+DumpAccessibilityTreeHelper::GetActualFileSuffix() {
   return FILE_PATH_LITERAL("-actual-mac.txt");
 }
 
+// static
 const base::FilePath::StringType
-DumpAccessibilityTreeHelper::GetExpectedFileSuffix()
-    const {
+DumpAccessibilityTreeHelper::GetExpectedFileSuffix() {
   return FILE_PATH_LITERAL("-expected-mac.txt");
 }
 
-const std::string DumpAccessibilityTreeHelper::GetAllowEmptyString() const {
+// static
+const std::string DumpAccessibilityTreeHelper::GetAllowEmptyString() {
   return "@MAC-ALLOW-EMPTY:";
 }
 
-const std::string DumpAccessibilityTreeHelper::GetAllowString() const {
+// static
+const std::string DumpAccessibilityTreeHelper::GetAllowString() {
   return "@MAC-ALLOW:";
 }
 
-const std::string DumpAccessibilityTreeHelper::GetDenyString() const {
+// static
+const std::string DumpAccessibilityTreeHelper::GetDenyString() {
   return "@MAC-DENY:";
 }