Revert "Turn on SkJumper except on Windows."

This reverts commit 957cf4594964c8f30e623d8c1b28ff63bef4ab33.

Reason for revert: crashes

Original change's description:
> Turn on SkJumper except on Windows.
> 
> ...only for our local testing.  No Skia users should be affected yet.
> 
> Change-Id: If1c46efe418458f747aafd6be8e2ae799c74b1c4
> Reviewed-on: https://skia-review.googlesource.com/8470
> Reviewed-by: Mike Klein <mtklein@chromium.org>
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> 

TBR=mtklein@chromium.org,herb@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: Id27f51c3b9356471b3178bbd63b021bd67a1d6fb
Reviewed-on: https://skia-review.googlesource.com/8477
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index 73bba1e..e478350 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -29,7 +29,7 @@
   skia_enable_android_framework_defines = false
   skia_enable_discrete_gpu = true
   skia_enable_effects = true
-  skia_enable_jumper = is_skia_standalone && !is_win
+  skia_enable_jumper = false
   skia_enable_gpu = true
   skia_enable_pdf = true
   skia_enable_tools = is_skia_standalone