Improve handling of clip stack ID

Change-Id: I1d5cf06d9b50c370f969a8778181fe94f7d35844
Reviewed-on: https://skia-review.googlesource.com/21061
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/gm/windowrectangles.cpp b/gm/windowrectangles.cpp
index ecc9304..dc5b93d 100644
--- a/gm/windowrectangles.cpp
+++ b/gm/windowrectangles.cpp
@@ -243,7 +243,7 @@
     reducedClip.drawStencilClipMask(ctx, rtc);
 
     // Now visualize the stencil mask by covering the entire render target. The regions inside
-    // window rectangless or outside the scissor should still have the initial checkerboard intact.
+    // window rectangles or outside the scissor should still have the initial checkerboard intact.
     // (This verifies we didn't spend any time modifying those pixels in the mask.)
     rtc->drawPaint(StencilOnlyClip(), std::move(paint), SkMatrix::I());
 }