Modify screen reader detection to use the AXEnhancedUserInterface attribute set on AXApplication when VoiceOver's turned on. This gives us the ability to turn on ax even after a render widget host has started.

BUG=none
TEST=manually with VoiceOver.  Launch Chrome, VoiceOver, windows, tabs (permuted order) and verify that ax is on.  This sometimes required navigation to a different page or efreshing the current page.
Review URL: http://codereview.chromium.org/6909013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@83940 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 21 insertions, 0 deletions

diff --git a/chrome/browser/chrome_browser_application_mac.mm b/chrome/browser/chrome_browser_application_mac.mm
index 7ba8cda..745e0ab 100644
--- a/chrome/browser/chrome_browser_application_mac.mm
+++ b/chrome/browser/chrome_browser_application_mac.mm
@@ -9,9 +9,13 @@
 #import "base/memory/scoped_nsobject.h"
 #import "base/sys_string_conversions.h"
 #import "chrome/app/breakpad_mac.h"
+#include "chrome/browser/accessibility/browser_accessibility_state.h"
 #import "chrome/browser/app_controller_mac.h"
+#include "chrome/browser/ui/browser_list.h"
 #import "chrome/browser/ui/cocoa/objc_method_swizzle.h"
 #import "chrome/browser/ui/cocoa/objc_zombie.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+#include "content/browser/renderer_host/render_view_host.h"
 
 // The implementation of NSExceptions break various assumptions in the
 // Chrome code.  This category defines a replacement for
@@ -384,4 +388,21 @@ BOOL SwizzleNSExceptionInit() {
   [super reportException:anException];
 }
 
+- (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute {
+  if ([attribute isEqualToString:@"AXEnhancedUserInterface"] &&
+      [value intValue] == 1) {
+    BrowserAccessibilityState::GetInstance()->OnScreenReaderDetected();
+    for (TabContentsIterator it;
+         !it.done();
+         ++it) {
+      if (TabContentsWrapper* contents = *it) {
+        if (RenderViewHost* rvh = contents->render_view_host()) {
+          rvh->EnableRendererAccessibility();
+        }
+      }
+    }
+  }
+  return [super accessibilitySetValue:value forAttribute:attribute];
+}
+
 @end