Fix eliding of LTR tab title in RTL UI under non-Windows Views.

ui/gfx/canvas.h

Index: ui/gfx/canvas.h
===================================================================
--- ui/gfx/canvas.h	(revision 144792)
+++ ui/gfx/canvas.h	(working copy)
@@ -363,7 +363,6 @@
   // Apply transformation on the canvas.
   void Transform(const ui::Transform& transform);
 
-#if defined(OS_WIN)
   // Draws the given string with the beginning and/or the end using a fade
   // gradient. When truncating the head
   // |desired_characters_to_truncate_from_head| specifies the maximum number of
@@ -375,7 +374,6 @@
       const gfx::Font& font,
       SkColor color,
       const gfx::Rect& display_rect);
-#endif
 
   skia::PlatformCanvas* platform_canvas() const { return owned_canvas_.get(); }
   SkCanvas* sk_canvas() const { return canvas_; }