Removing unnecessary ValidateStack in the UnwindStateStack

Removing unnecessary ValidateStack that was failing as it was happening
in midway during a reset stack process.

Bug: 1000044
Change-Id: I8b646f60abea1d21d3d9925771d10c3330bc9c82
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1782501
Commit-Queue: Juanmi Huertas <juanmihd@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693171}

third_party/blink/renderer/modules/canvas/canvas2d/base_rendering_context_2d.cc

@@ -125,7 +125,6 @@ void BaseRenderingContext2D::UnwindStateStack() {
         sk_canvas->restore();
     }
   }
-  ValidateStateStack();
 }
 
 void BaseRenderingContext2D::Reset() {