Add kAAHairline to GpuPathRenderers

With the upcoming ccpr stroking, this will no longer be the only path
renderer that can handle hairlines.

Bug: skia:
Change-Id: I45b30ccd578bee1388a3a07a234af76a19768de6
Reviewed-on: https://skia-review.googlesource.com/142272
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/tools/flags/SkCommonFlags.cpp b/tools/flags/SkCommonFlags.cpp
index 459f655..9a8194c 100644
--- a/tools/flags/SkCommonFlags.cpp
+++ b/tools/flags/SkCommonFlags.cpp
@@ -161,10 +161,10 @@
 
 DEFINE_bool(noGS, false, "Disables support for geometry shaders.");
 
-DEFINE_string(pr, "default",
+DEFINE_string(pr, "all",
               "Set of enabled gpu path renderers. Defined as a list of: "
-              "[~]all [~]default [~]dashline [~]nvpr [~]aaconvex "
-              "[~]aalinearizing [~]small [~]tess]");
+              "[~]none [~]dashline [~]nvpr [~]ccpr [~]aahairline [~]aaconvex [~]aalinearizing "
+              "[~]small [~]tess] [~]all");
 
 void SetCtxOptionsFromCommonFlags(GrContextOptions* ctxOptions) {
     static std::unique_ptr<SkExecutor> gGpuExecutor = (0 != FLAGS_gpuThreads)