Select theme resources from ResourceBundle at requested scale factor.

ui/base/resource/resource_handle.h

Index: ui/base/resource/resource_handle.h
diff --git a/ui/base/resource/resource_handle.h b/ui/base/resource/resource_handle.h
index b40741e7599b48537f1e95c21c2ac85d62965500..5349c4e1bfc4756fe2a5271b10344cd9cbf097b7 100644
--- a/ui/base/resource/resource_handle.h
+++ b/ui/base/resource/resource_handle.h
@@ -29,8 +29,14 @@ class UI_EXPORT ResourceHandle {
   static const float kScaleFactor100x;
   static const float kScaleFactor200x;
 
+  // This scale factor is used for non-image resources.
+  static const float kScaleFactorNone;

[tony, 2012/05/11 21:22:03]

Can we combine the scale factors into an enum?  The only valid values seem to be
are 1, 2 and None.  Also, I find it confusing that the variable names are 100x
and 200x since that sounds like 100 and 200 times bigger. 1x and 2x would make
more sense and match the other code.

[sail, 2012/05/11 21:28:50]

This used to be 1x and 2x but Joi made a good point that we need to support 1.4x
and 1.8x for Windows 8 Metro. Using a percentage system makes that easier to
ready.

+
   virtual ~ResourceHandle() {}
 
+  // Returns true if the DataPack contains a resource with id |resource_id|.
+  virtual bool HasResource(uint16 resource_id) const = 0;
+
   // Get resource by id |resource_id|, filling in |data|.
   // The data is owned by the DataPack object and should not be modified.
   // Returns false if the resource id isn't found.