Revert "Threaded generation of software paths"

This reverts commit 76323bc0615044a5921afef0e19a350f3d04ffe0.

Reason for revert: Breaking NUC bots in threaded gm comparison:

https://chromium-swarm.appspot.com/task?id=382e589753187f10&refresh=10



Original change's description:
> Threaded generation of software paths
> 
> All information needed by the thread is captured by the prepare
> callback object, the lambda captures a pointer to that, and does the
> mask render. Once it's done, it signals the semaphore (also owned by the
> callback). The callback defers the semaphore wait even longer (into the
> ASAP upload), so the odds of waiting for the thread are REALLY low.
> 
> Also did a bunch of cleanup along the way, and put in some trace markers
> so we can monitor how well this is working.
> 
> Traces of a GM that includes GPU and SW path rendering (path-reverse):
> 
> Original:
>     https://screenshot.googleplex.com/f5BG3901tQg.png
> Threaded, with wait in the callback (notice pre flush callback blocking):
>     https://screenshot.googleplex.com/htOSZFE2s04.png
> Current version, with wait deferred to ASAP upload function:
>     https://screenshot.googleplex.com/GHjD0U3C34q.png
> 
> Bug: skia:
> Change-Id: I3d5a230bbd68eb35e1f0574b308485c691435790
> Reviewed-on: https://skia-review.googlesource.com/36560
> Commit-Queue: Brian Osman <brianosman@google.com>
> Reviewed-by: Brian Salomon <bsalomon@google.com>

TBR=egdaniel@google.com,mtklein@google.com,bsalomon@google.com,robertphillips@google.com,brianosman@google.com

Change-Id: Icac0918a3771859f671b69ae07ae0fedd3ebb3db
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/38560
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index ef3bdf776f..ab7c689309 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -30,7 +30,6 @@
 #include "SkCodec.h"
 #include "SkCommonFlags.h"
 #include "SkCommonFlagsConfig.h"
-#include "SkCommonFlagsGpuThreads.h"
 #include "SkCommonFlagsPathRenderer.h"
 #include "SkData.h"
 #include "SkDebugfTracer.h"
@@ -1140,7 +1139,6 @@ int main(int argc, char** argv) {
 #if SK_SUPPORT_GPU
     GrContextOptions grContextOpts;
     grContextOpts.fGpuPathRenderers = CollectGpuPathRenderersFromFlags();
-    grContextOpts.fExecutor = GpuExecutorForTools();
     gGrFactory.reset(new GrContextFactory(grContextOpts));
 #endif