Use string literal style for shader string in WebGLCompatibilityTest
Use string literal style for shader string in WebGLCompatibilityTest

Bug: None
Change-Id: I75255cfda3793c539ac8a6ee2c50b8526bfc9286
Reviewed-on: https://chromium-review.googlesource.com/c/1493113
Commit-Queue: Shrek Shao <7ae796039b2f0529765a6c4b0ab8ce931d949d23@google.com>
Reviewed-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@google.com>

ppy/angle,ppy/angle,ppy/angle,ppy/angle