Disable 2 GLHelperPixelTest testcases
Disable 2 GLHelperPixelTest testcases

Disable GLHelperPixelTest.CropScaleReadbackAndCleanTextureTest and
GLHelperPixelTest.ScaleTest. They are flaky.

TBR=kbr@chromium.org
BUG=583384

Review URL: https://codereview.chromium.org/1667793003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#373490}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk