Add option to control maximum GrBatch lookback

dm/DMSrcSink.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "DMSrcSink.h"
 #include "SamplePipeControllers.h"
 #include "SkAndroidCodec.h"
@@ skipping 792 matching lines @@
 
 int GPUSink::enclave() const {
     return fThreaded ? kAnyThread_Enclave : kGPU_Enclave;
 }
 
 void PreAbandonGpuContextErrorHandler(SkError, void*) {}
 
 DEFINE_bool(imm, false, "Run gpu configs in immediate mode.");
 DEFINE_bool(batchClip, false, "Clip each GrBatch to its device bounds for testing.");
 DEFINE_bool(batchBounds, false, "Draw a wireframe bounds of each GrBatch.");
+DEFINE_int32(batchLookback, -1, "Maximum GrBatch lookback for combining, negative means default.");
 
 Error GPUSink::draw(const Src& src, SkBitmap* dst, SkWStream*, SkString* log) const {
     GrContextOptions grOptions;
-    if (FLAGS_imm) {
-        grOptions.fImmediateMode = true;
-    }
-    if (FLAGS_batchClip) {
-        grOptions.fClipBatchToBounds = true;
-    }
+    grOptions.fImmediateMode = FLAGS_imm;
+    grOptions.fClipBatchToBounds = FLAGS_batchClip;
+    grOptions.fDrawBatchBounds = FLAGS_batchBounds;
+    grOptions.fMaxBatchLookback = FLAGS_batchLookback;
 
-    if (FLAGS_batchBounds) {
-        grOptions.fDrawBatchBounds = true;
-    }
     src.modifyGrContextOptions(&grOptions);
 
     GrContextFactory factory(grOptions);
     const SkISize size = src.size();
     const SkImageInfo info =
         SkImageInfo::Make(size.width(), size.height(), kN32_SkColorType, kPremul_SkAlphaType);
     SkAutoTUnref<SkSurface> surface(
             NewGpuSurface(&factory, fContextType, fContextOptions, fGpuAPI, info, fSampleCount,
                           fUseDIText));
     if (!surface) {
@@ skipping 432 matching lines @@
             skr.visit<void>(i, drawsAsSingletonPictures);
         }
         SkAutoTUnref<SkPicture> macroPic(macroRec.endRecordingAsPicture());
 
         canvas->drawPicture(macroPic);
         return "";
     });
 }
 
 }  // namespace DM