Reland "Add --skip_cpu and --skip_gpu options to tests"

NOTRY=true

BUG=skia:2074
R=djsollen@google.com, mtklein@google.com

Author: borenet@google.com

Review URL: https://codereview.chromium.org/135163004

git-svn-id: http://skia.googlecode.com/svn/trunk@13237 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/Test.h b/tests/Test.h
index 2dc7c66..0a9c306 100644
--- a/tests/Test.h
+++ b/tests/Test.h
@@ -64,7 +64,7 @@
 
         static SkString GetResourcePath();
 
-        virtual bool isThreadsafe() const { return true; }
+        virtual bool isGPUTest() const { return false; }
 
     protected:
         virtual void onGetName(SkString*) = 0;
@@ -82,7 +82,7 @@
         GpuTest() : Test() {}
         static GrContextFactory* GetGrContextFactory();
         static void DestroyContexts();
-        virtual bool isThreadsafe() const { return false; }
+        virtual bool isGPUTest() const { return true; }
     private:
     };