Wire up windowless plugins. Mostly Mac related, some cross

app/gfx/canvas.cc

Index: app/gfx/canvas.cc
===================================================================
--- app/gfx/canvas.cc	(revision 20445)
+++ app/gfx/canvas.cc	(working copy)
@@ -221,16 +221,6 @@
                 l10n_util::DefaultCanvasTextAlignment());
 }
 
-#if defined(OS_MACOSX)
-void Canvas::DrawStringInt(const std::wstring& text,
-                           const gfx::Font& font,
-                           const SkColor& color,
-                           int x, int y, int w, int h,
-                           int flags) {
-  NOTIMPLEMENTED();
-}
-#endif
-
 void Canvas::TileImageInt(const SkBitmap& bitmap, int x, int y, int w, int h) {
   TileImageInt(bitmap, 0, 0, x, y, w, h);
 }