MacViews: Fix accessibility hit tests, provide AXTitle

ui/views/cocoa/bridged_native_widget.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ui/views/cocoa/bridged_native_widget.h"
 
 #import <objc/runtime.h>
 
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
@@ skipping 10 matching lines @@
 #import "ui/views/cocoa/bridged_content_view.h"
 #import "ui/views/cocoa/views_nswindow_delegate.h"
 #include "ui/views/widget/native_widget_mac.h"
 #include "ui/views/ime/input_method_bridge.h"
 #include "ui/views/ime/null_input_method.h"
 #include "ui/views/view.h"
 #include "ui/views/views_delegate.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_aura_utils.h"
 
+// The NSView that hosts the composited CALayer drawing the UI. It fills the
+// window but is not hittable so that accessibility hit tests always go to the
+// BridgedContentView.
+@interface ViewsCompositorSuperview : NSView
+@end
+
+@implementation ViewsCompositorSuperview
+- (NSView*)hitTest:(NSPoint)aPoint {
+  return nil;
+}
+@end
+
 namespace {
 
 int kWindowPropertiesKey;
 
 float GetDeviceScaleFactorFromView(NSView* view) {
   gfx::Display display =
       gfx::Screen::GetScreenFor(view)->GetDisplayNearestWindow(view);
   DCHECK(display.is_valid());
   return display.device_scale_factor();
 }
@@ skipping 642 matching lines @@
     return;
   }
   compositor_widget_->ResetNSView();
   compositor_.reset();
   compositor_widget_.reset();
 }
 
 void BridgedNativeWidget::AddCompositorSuperview() {
   DCHECK(!compositor_superview_);
   compositor_superview_.reset(
-      [[NSView alloc] initWithFrame:[bridged_view_ bounds]]);
+      [[ViewsCompositorSuperview alloc] initWithFrame:[bridged_view_ bounds]]);
 
   // Size and resize automatically with |bridged_view_|.
   [compositor_superview_
       setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
 
   // Enable HiDPI backing when supported (only on 10.7+).
   if ([compositor_superview_ respondsToSelector:
       @selector(setWantsBestResolutionOpenGLSurface:)]) {
     [compositor_superview_ setWantsBestResolutionOpenGLSurface:YES];
   }
@@ skipping 28 matching lines @@
       window_, &kWindowPropertiesKey);
   if (!properties) {
     properties = [NSMutableDictionary dictionary];
     objc_setAssociatedObject(window_, &kWindowPropertiesKey,
                              properties, OBJC_ASSOCIATION_RETAIN);
   }
   return properties;
 }
 
 }  // namespace views