Add a new GetInstance() method for remaining files with singleton classes under chrome/browser.

chrome/browser/accessibility/browser_accessibility_state.cc

Index: chrome/browser/accessibility/browser_accessibility_state.cc
diff --git a/chrome/browser/accessibility/browser_accessibility_state.cc b/chrome/browser/accessibility/browser_accessibility_state.cc
index 83f81f9b601e6abc866aa29f6eed0dce6c3caa17..403e5ff258f6f77554443b7a942c99542e78cafe 100644
--- a/chrome/browser/accessibility/browser_accessibility_state.cc
+++ b/chrome/browser/accessibility/browser_accessibility_state.cc
@@ -12,6 +12,11 @@ BrowserAccessibilityState::BrowserAccessibilityState()
 BrowserAccessibilityState::~BrowserAccessibilityState() {
 }
 
+// static
+BrowserAccessibilityState* BrowserAccessibilityState::GetInstance() {
+  return Singleton<BrowserAccessibilityState>::get();
+}
+
 void BrowserAccessibilityState::OnScreenReaderDetected() {
   screen_reader_active_ = true;
 }