Revert of Hairline batch (patchset #17 id:360001 of https://codereview.chromium.org/876673002/)

Reason for revert:
still a performance regression

Original issue's description:
> Hairline batch
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/6eff8701f027016fbb3147412ec2292dcec2b7f5
>
> Committed: https://skia.googlesource.com/skia/+/658d55cd6121c67488aaf5d0832c9712737f26a5

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

Review URL: https://codereview.chromium.org/882883003
diff --git a/src/gpu/GrBatchTarget.cpp b/src/gpu/GrBatchTarget.cpp
index 1b68923..6a31353 100644
--- a/src/gpu/GrBatchTarget.cpp
+++ b/src/gpu/GrBatchTarget.cpp
@@ -32,20 +32,17 @@
     fFlushBuffer.reset();
 }*/
 
-void GrBatchTarget::flushNext(int n) {
-    for (; n > 0; n--) {
-        SkDEBUGCODE(bool verify =) fIter.next();
-        SkASSERT(verify);
-        GrProgramDesc desc;
-        BufferedFlush* bf = fIter.get();
-        const GrPipeline* pipeline = bf->fPipeline;
-        const GrPrimitiveProcessor* primProc = bf->fPrimitiveProcessor.get();
-        fGpu->buildProgramDesc(&desc, *primProc, *pipeline, pipeline->descInfo(),
-                               bf->fBatchTracker);
+void GrBatchTarget::flushNext() {
+    fIter.next();
+    GrProgramDesc desc;
+    BufferedFlush* bf = fIter.get();
+    const GrPipeline* pipeline = bf->fPipeline;
+    const GrPrimitiveProcessor* primProc = bf->fPrimitiveProcessor.get();
+    fGpu->buildProgramDesc(&desc, *primProc, *pipeline, pipeline->descInfo(),
+                           bf->fBatchTracker);
 
-        GrGpu::DrawArgs args(primProc, pipeline, &desc, &bf->fBatchTracker);
-        for (int i = 0; i < bf->fDraws.count(); i++) {
-            fGpu->draw(args, bf->fDraws[i]);
-        }
+    GrGpu::DrawArgs args(primProc, pipeline, &desc, &bf->fBatchTracker);
+    for (int i = 0; i < bf->fDraws.count(); i++) {
+        fGpu->draw(args, bf->fDraws[i]);
     }
 }