Revert "Make mock GrContext unit testable."

This reverts commit 993e7e25217df05d63c3354c817e8bd18ea3738b.

Reason for revert: Seeing if this fixes the NexusPlayer bots

Original change's description:
> Make mock GrContext unit testable.
> 
> Bug: skia:
> Change-Id: I959122f1f2c390832ab1033bcdbdd2ca6cfc0419
> Reviewed-on: https://skia-review.googlesource.com/20699
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

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

Change-Id: I25ed9329962d930fe38108f779ff7083e0e4847e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/21731
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/BUILD.gn b/BUILD.gn
index d0bfa57710..9b2859ce65 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -956,7 +956,6 @@ if (skia_enable_tools) {
         "tools/gpu/gl/debug/GrTextureObj.cpp",
         "tools/gpu/gl/debug/GrTextureUnitObj.cpp",
         "tools/gpu/gl/null/NullGLTestContext.cpp",
-        "tools/gpu/mock/MockTestContext.cpp",
       ]
       libs = []