aura-x11: Add custom web cursor support.

ui/aura/root_window_host_linux.h

Index: ui/aura/root_window_host_linux.h
diff --git a/ui/aura/root_window_host_linux.h b/ui/aura/root_window_host_linux.h
index 8fc4fa9a4dde7240b2ad86c0d26a8972fd7bcb6e..923e7014c18cd057d84b49acb63b1a325f44ffdf 100644
--- a/ui/aura/root_window_host_linux.h
+++ b/ui/aura/root_window_host_linux.h
@@ -38,6 +38,7 @@ class RootWindowHostLinux : public RootWindowHost,
   virtual void SetCapture() OVERRIDE;
   virtual void ReleaseCapture() OVERRIDE;
   virtual void SetCursor(gfx::NativeCursor cursor_type) OVERRIDE;
+  virtual void SetCustomCursor(const gfx::PlatformCursor& cursor) OVERRIDE;
   virtual void ShowCursor(bool show) OVERRIDE;
   virtual gfx::Point QueryMouseLocation() OVERRIDE;
   virtual bool ConfineCursorToRootWindow() OVERRIDE;
@@ -70,6 +71,9 @@ class RootWindowHostLinux : public RootWindowHost,
   // Current Aura cursor.
   gfx::NativeCursor current_cursor_;
 
+  // Current custom platform cursor.
+  gfx::PlatformCursor custom_cursor_;
+
   // Is the cursor currently shown?
   bool cursor_shown_;