Fix accessibility coordinates within iframes.

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 08ec4da6886e1c093bad1c74578b2ff93f51d03b..f5ba910845f78ae51085f52665df460c890e43b1 100644
--- a/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
+++ b/content/browser/accessibility/dump_accessibility_tree_helper_mac.mm
@@ -10,9 +10,12 @@
 #include "base/utf_string_conversions.h"
 #include "content/browser/accessibility/browser_accessibility_cocoa.h"
 #include "content/browser/accessibility/browser_accessibility_mac.h"
+#include "content/browser/accessibility/browser_accessibility_manager.h"
 
 namespace content {
+
 namespace {
+
 string16 Format(BrowserAccessibility* node,
                 const char *prefix,
                 SEL selector,
@@ -26,8 +29,43 @@ string16 Format(BrowserAccessibility* node,
   NSString* tmp = [NSString stringWithFormat:format_str, value];
   return UTF8ToUTF16([tmp cStringUsingEncoding:NSUTF8StringEncoding]);
 }
+
+string16 FormatPosition(BrowserAccessibility* node) {
+  // The NSAccessibility position of an object is in global coordinates and
+  // based on the lower-left corner of the object. To make this easier and less
+  // confusing, convert it to local window coordinates using the top-left
+  // corner when dumping the position.
+  BrowserAccessibility* root = node->manager()->GetRoot();
+  BrowserAccessibilityCocoa* cocoa_root = root->ToBrowserAccessibilityCocoa();
+  NSPoint root_position = [[cocoa_root position] pointValue];
+  NSSize root_size = [[cocoa_root size] sizeValue];
+  int root_top = -static_cast<int>(root_position.y + root_size.height);
+  int root_left = static_cast<int>(root_position.x);
+
+  BrowserAccessibilityCocoa* cocoa_node = node->ToBrowserAccessibilityCocoa();
+  NSPoint node_position = [[cocoa_node position] pointValue];
+  NSSize node_size = [[cocoa_node size] sizeValue];
+
+  NSString* position_str =
+      [NSString stringWithFormat:@"position=(%d, %d)",
+                static_cast<int>(node_position.x - root_left),
+                static_cast<int>(
+                    -node_position.y - node_size.height - root_top)];
+  return UTF8ToUTF16([position_str cStringUsingEncoding:NSUTF8StringEncoding]);
 }
 
+string16 FormatSize(BrowserAccessibility* node) {
+  BrowserAccessibilityCocoa* cocoa_node = node->ToBrowserAccessibilityCocoa();
+  NSSize node_size = [[cocoa_node size] sizeValue];
+  NSString* size_str =
+      [NSString stringWithFormat:@"size=(%d, %d)",
+                static_cast<int>(node_size.width),
+                static_cast<int>(node_size.height)];
+  return UTF8ToUTF16([size_str cStringUsingEncoding:NSUTF8StringEncoding]);
+}
+
+}  // namespace
+
 void DumpAccessibilityTreeHelper::Initialize() {}
 
 string16 DumpAccessibilityTreeHelper::ToString(BrowserAccessibility* node,
@@ -63,13 +101,14 @@ string16 DumpAccessibilityTreeHelper::ToString(BrowserAccessibility* node,
   Add(false, Format(node, "numberOfCharacters='",
                     @selector(numberOfCharacters), "'"));
   Add(false, Format(node, "orientation='", @selector(orientation), "'"));
-  Add(false, Format(node, "position='", @selector(position), "'"));
   Add(false, Format(node, "required='", @selector(required), "'"));
-  Add(false, Format(node, "size='", @selector(size), "'"));
   Add(false, Format(node, "url='", @selector(url), "'"));
   Add(false, Format(node, "visibleCharacterRange='",
                     @selector(visibleCharacterRange), "'"));
   Add(false, Format(node, "visited='", @selector(visited), "'"));
+  Add(false, FormatPosition(node));
+  Add(false, FormatSize(node));
+
   return ASCIIToUTF16(prefix) + FinishLine() + ASCIIToUTF16("\n");
 }