Reland of add a ClassID function to GrBatch (patchset #1 id:1 of https://codereview.chromium.org/1353043002/ )

Reason for revert:
DEPS roll seems to have landed w/o this revert, so revert it again

Original issue's description:
> Revert of add a ClassID function to GrBatch (patchset #5 id:80001 of https://codereview.chromium.org/1352813003/ )
>
> Reason for revert:
> Speculative revert to unblock DEPS roll
>
> Original issue's description:
> > add a ClassID function to GrBatch
> >
> > BUG=skia:
> >
> > Committed: https://skia.googlesource.com/skia/+/4078d529e9e199eea13456db7bf3a63a104ab5b9
> >
> > Committed: https://skia.googlesource.com/skia/+/eb44d53cf96a7eaf103a98d76079ce1f5495e343
>
> TBR=robertphillips@google.com,bsalomon@google.com,joshualitt@google.com,joshualitt@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/48e3a45ade15c52c0c1a10cb00907dd444897745

TBR=robertphillips@google.com,bsalomon@google.com,joshualitt@google.com,joshualitt@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1344373005
diff --git a/tests/GrPorterDuffTest.cpp b/tests/GrPorterDuffTest.cpp
index 1328272a..a61ab548 100644
--- a/tests/GrPorterDuffTest.cpp
+++ b/tests/GrPorterDuffTest.cpp
@@ -1093,7 +1093,13 @@
 }
 
 static void test_lcd_coverage_fallback_case(skiatest::Reporter* reporter, const GrCaps& caps) {
-    class : public GrVertexBatch {
+    class TestLCDCoverageBatch: public GrVertexBatch {
+    public:
+        DEFINE_BATCH_CLASS_ID
+
+        TestLCDCoverageBatch() : INHERITED(ClassID()) {}
+
+    private:
         void getInvariantOutputColor(GrInitInvariantOutput* out) const override {
             out->setKnownFourComponents(GrColorPackRGBA(123, 45, 67, 221));
         }
@@ -1108,6 +1114,7 @@
         bool onCombineIfPossible(GrBatch*, const GrCaps&) override  { return false; }
         void onPrepareDraws(Target*) override {};
 
+        typedef GrVertexBatch INHERITED;
     } testLCDCoverageBatch;
 
     GrProcOptInfo colorPOI, covPOI;