Add a context field to the accessibility extension API.

chrome/browser/accessibility/accessibility_events.h

Index: chrome/browser/accessibility/accessibility_events.h
===================================================================
--- chrome/browser/accessibility/accessibility_events.h	(revision 112880)
+++ chrome/browser/accessibility/accessibility_events.h	(working copy)
@@ -59,11 +59,18 @@
 
   const std::string& name() const { return name_; }
 
+  const std::string& context() const { return context_; }
+  void set_context(const std::string& context) { context_ = context; }

[hashimoto, 2011/12/07 23:07:35]

Instead of exposing the setter, how about setting |context_| by ctors?
It will be more consistent with |name_|

[dmazzoni, 2011/12/07 23:34:12]

Sure, I changed it to be in the constructor.

Now there are a couple of subclasses where a context probably isn't needed, so
the subclass passes std::string(), does that seem reasonable?

[hashimoto, 2011/12/08 00:04:13]

How about having two ctors (two argument version and three argument version) ?
Or having single two-argument ctor while having set_context as a protected
method and using it to set |context| in subclasses' ctors.

+
  protected:
   AccessibilityControlInfo(Profile* profile, const std::string& control_name);
 
   // The name of the control, like "OK" or "Password".
   std::string name_;
+
+  // A string describing the context of the control, such as the name of
+  // the group or toolbar it's contained in.
+  std::string context_;
 };
 
 // Accessibility information about a window passed to onWindowOpened