Correct DirectCompositionSurfaceWin::AllowTearing() function

The Boolean result of this function was accidentally reversed in
https://chromium-review.googlesource.com/c/chromium/src/+/2597637.
This CL corrects the logic.

For some reason, this wrong AllowTearing flag prevents hardware overlay
promotions on Surface Book while the other laptop like Blazer is fine.
These two are the only devices I checked.

Bug: 43611
Change-Id: Ib6f27d74d55e0977df840e1f10001ccc01ca5227
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2606292Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Maggie Chen <magchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839804}

ui/gl/direct_composition_surface_win.cc

@@ -653,7 +653,7 @@ bool DirectCompositionSurfaceWin::IsSwapChainTearingSupported() {
 // static
 bool DirectCompositionSurfaceWin::AllowTearing() {
   // Swap chain tearing is used only if vsync is disabled explicitly.
-  return features::UseGpuVsync() &&
+  return !features::UseGpuVsync() &&
          DirectCompositionSurfaceWin::IsSwapChainTearingSupported();
 }