Revert changes to GrContext::resolveRenderTarget

TBR=joshualitt@google.com,egdaniel@google.com

Review URL: https://codereview.chromium.org/700483003
Detect Mesa OpenGL ES

Original-Author: Henry Song <henrysong@samsung.com>

Review URL: https://codereview.chromium.org/700633002
Improve quality of distance field rendering
- Update spacing of LODs to get better results scaling up to 256
- Remove unnecessary "bolding" from dftext
- Add debug colors for dftext LODs

BUG=skia:2933,skia:2935

Review URL: https://codereview.chromium.org/703463002
Temporary fix to remove drawrect call from GpuGL

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/d4a5c2028117c100ccf44263c0118a0b4745f627

Review URL: https://codereview.chromium.org/694933002
Rename and clarify semantics of GrContext::resolveRenderTarget.

Review URL: https://codereview.chromium.org/696293004
Optimize SkRect::sort()

This optimization can reduce comparison and assignments. For
geo_rect_sort benchmark, performance improved to 1.63us from 3.28us.

BUG=skia:

Review URL: https://codereview.chromium.org/695443005