Added boundary check for array access as a short-term way of fixing the bug of out-of-bounds reads into the array
Added boundary check for array access as a short-term way of fixing the bug of out-of-bounds reads into the array

BUG=chromium:529527, chromium:529552

Review URL: https://codereview.webrtc.org/1338993003

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#9930}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: fc9dd1710d1e9f52846931cabed97134393d0b82

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