When GrAAConvesTesselator was merging the first and last point of the array, it was deleting the last point without checking to see if any of the previous points shared the same index. This led to continuing to use the index of a deleted point and thus referencing memory past the end of the vertex array.
When GrAAConvesTesselator was merging the first and last point of the array, it was deleting the last point without checking to see if any of the previous points shared the same index. This led to continuing to use the index of a deleted point and thus referencing memory past the end of the vertex array.

BUG=chromium:505227

Review URL: https://codereview.chromium.org/1225683008

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