Fix focus and bounds calculations for guest frames.

content/browser/accessibility/browser_accessibility_cocoa.mm

 // Copyright (c) 2012 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.
 
 #include <execinfo.h>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/strings/string16.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/app/strings/grit/content_strings.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/browser/accessibility/browser_accessibility_manager_mac.h"
 #include "content/public/common/content_client.h"
 #import "ui/accessibility/platform/ax_platform_node_mac.h"
 
 // See http://openradar.appspot.com/9896491. This SPI has been tested on 10.5,
 // 10.6, and 10.7. It allows accessibility clients to observe events posted on
 // this object.
 extern "C" void NSAccessibilityUnregisterUniqueIdForUIElement(id element);
 
 using ui::AXNodeData;
 using content::BrowserAccessibility;
+using content::BrowserAccessibilityDelegate;
 using content::BrowserAccessibilityManager;
 using content::BrowserAccessibilityManagerMac;
 using content::ContentClient;
 typedef ui::AXStringAttribute StringAttribute;
 
 namespace {
 
 // Returns an autoreleased copy of the AXNodeData's attribute.
 NSString* NSStringForStringAttribute(
     BrowserAccessibility* browserAccessibility,
@@ skipping 463 matching lines @@
   return browserAccessibility_->manager() ?
       browserAccessibility_->manager()->delegate() :
       nil;
 }
 
 - (NSPoint)pointInScreen:(NSPoint)origin
                     size:(NSSize)size {
   if (!browserAccessibility_)
     return NSZeroPoint;
 
+  // Get the delegate for the topmost BrowserAccessibilityManager, because
+  // that's the only one that can convert points to their origin in the screen.
+  BrowserAccessibilityManager* manager = browserAccessibility_->manager();
+  BrowserAccessibility* root = manager->GetRoot();
+  while (root->GetParent())
+    root = root->GetParent()->manager()->GetRoot();

[aboxhall, 2015/01/15 05:08:25]

That's an impressive method chain! Any chance of any nulls in here? (I guess,
any chance of manager() or GetRoot() returning null.)

[dmazzoni, 2015/01/15 21:02:33]

Great question!
* root->GetParent() can't be NULL because of the loop condition
* a BrowserAccessibility object is always owned by a
BrowserAccessibilityManager; it's never NULL
* A BrowserAccessibilityManager always has a root, it's never NULL

So we're okay.

However, manager->delegate() may be NULL, so I'll fix that below.

+  manager = root->manager();
+  BrowserAccessibilityDelegate* delegate = manager->delegate();
+
   gfx::Rect bounds(origin.x, origin.y, size.width, size.height);
-  gfx::Point point = [self delegate]->AccessibilityOriginInScreen(bounds);
+  gfx::Point point = delegate->AccessibilityOriginInScreen(bounds);
   return NSMakePoint(point.x(), point.y());
 }
 
 // Returns a string indicating the NSAccessibility role of this object.
 - (NSString*)role {
   ui::AXRole role = [self internalRole];
   if (role == ui::AX_ROLE_CANVAS &&
       browserAccessibility_->GetBoolAttribute(
           ui::AX_ATTR_CANVAS_HAS_FALLBACK)) {
     return NSAccessibilityGroupRole;
@@ skipping 995 matching lines @@
     return [super hash];
   return browserAccessibility_->GetId();
 }
 
 - (BOOL)accessibilityShouldUseUniqueId {
   return YES;
 }
 
 @end