Introduce GrBatch subclasses GrDrawBatch and GrVertexBatch to prepare for non-drawing batches

src/gpu/GrTargetCommands.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 "GrTargetCommands.h"
 
 #include "GrBufferedDrawTarget.h"
@@ skipping 12 matching lines @@
     }
 
     GrGpu* gpu = bufferedDrawTarget->getGpu();
 
     // Loop over all batches and generate geometry
     CmdBuffer::Iter genIter(fCmdBuffer);
     while (genIter.next()) {
         if (Cmd::kDrawBatch_CmdType == genIter->type()) {
             DrawBatch* db = reinterpret_cast<DrawBatch*>(genIter.get());
             fBatchTarget.resetNumberOfDraws();
-            db->batch()->generateGeometry(&fBatchTarget);
-            db->batch()->setNumberOfDraws(fBatchTarget.numberOfDraws());
+            // TODO: encapsulate the specialization of GrVertexBatch in GrVertexBatch so that we can
+            // remove this cast. Currently all GrDrawBatches are in fact GrVertexBatch.
+            GrVertexBatch* vertexBatch = static_cast<GrVertexBatch*>(db->batch());
+
+            vertexBatch->generateGeometry(&fBatchTarget);
+            vertexBatch->setNumberOfDraws(fBatchTarget.numberOfDraws());
         }
     }
 
     fBatchTarget.preFlush();
 
     CmdBuffer::Iter iter(fCmdBuffer);
 
     while (iter.next()) {
         iter->execute(gpu);
     }
@@ skipping 24 matching lines @@
                               fState->fBatchTracker);
         fState->fCompiled = true;
     }
     GrPathRendering::DrawPathArgs args(fState->fPrimitiveProcessor.get(), fState->getPipeline(),
                                        &fState->fDesc, &fState->fBatchTracker, &fStencilSettings);
     gpu->pathRendering()->drawPaths(args, this->pathRange(), fIndices, fIndexType, fTransforms,
                                     fTransformType, fCount);
 }
 
 void GrTargetCommands::DrawBatch::execute(GrGpu* gpu) {
-    fBatchTarget->flushNext(fBatch->numberOfDraws());
+    // TODO: encapsulate the specialization of GrVertexBatch in GrVertexBatch so that we can
+    // remove this cast. Currently all GrDrawBatches are in fact GrVertexBatch.
+    const GrVertexBatch* vertexBatch = static_cast<const GrVertexBatch*>(fBatch.get());
+    fBatchTarget->flushNext(vertexBatch->numberOfDraws());
 }
 
 void GrTargetCommands::Clear::execute(GrGpu* gpu) {
     if (GrColor_ILLEGAL == fColor) {
         gpu->discard(this->renderTarget());
     } else {
         gpu->clear(fRect, fColor, this->renderTarget());
     }
 }
 
 void GrTargetCommands::ClearStencilClip::execute(GrGpu* gpu) {
     gpu->clearStencilClip(fRect, fInsideClip, this->renderTarget());
 }
 
 void GrTargetCommands::CopySurface::execute(GrGpu* gpu) {
     gpu->copySurface(this->dst(), this->src(), fSrcRect, fDstPoint);
 }