Revert "Turn on SkJumper all the time."

This reverts commit 135555101cbde68656f028c41506113374a4026f.

Reason for revert: forgot g3, seems to break Chrome NaCl builders?

https://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20Win/builds/15969/steps/compile/logs/stdio

Original change's description:
> Turn on SkJumper all the time.
> 
> If the previous CL sticks, it's now easy to turn on SkJumper everywhere:
> I was mostly holding back because of build system complexity.
> 
> This has the main effect of turning on SkJumper in Chromium.
> It's already been on on our local test bots and on Android framework.
> 
> Change-Id: I7fbfc6aaaa7dace9c3f2cb509583c69b10997dbf
> Reviewed-on: https://skia-review.googlesource.com/9380
> 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: I69747e9e75b2a8e3d78f6c150c9b6d6453e00632
Reviewed-on: https://skia-review.googlesource.com/9444
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index d5c7bc7..a4e4a2e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -30,6 +30,7 @@
   skia_enable_android_framework_defines = false
   skia_enable_discrete_gpu = true
   skia_enable_effects = true
+  skia_enable_jumper = is_skia_dev_build
   skia_enable_gpu = true
   skia_enable_pdf = true
   skia_enable_tools = is_skia_dev_build
@@ -499,6 +500,16 @@
   ]
 }
 
+optional("jumper") {
+  enabled = skia_enable_jumper
+  public_defines = [ "SK_JUMPER" ]
+  sources = [
+    "src/jumper/SkJumper.cpp",
+    "src/jumper/SkJumper_generated.cpp",
+    "src/jumper/SkJumper_stages.cpp",
+  ]
+}
+
 optional("typeface_freetype") {
   enabled = skia_use_freetype
 
@@ -558,6 +569,7 @@
     ":gpu",
     ":hsw",
     ":jpeg",
+    ":jumper",
     ":none",
     ":pdf",
     ":png",