Make GrVertexBatch objects hold their own draws during GrDrawTarget flush

src/gpu/batches/GrDrawBatch.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawBatch_DEFINED
 #define GrDrawBatch_DEFINED
 
 #include "GrBatch.h"
 #include "GrPipeline.h"
 
 struct GrInitInvariantOutput;
 
 /**
+ * GrDrawBatches are flushed in two phases (preDraw, and draw). In preDraw uploads to GrGpuResources
+ * and draws are determined and scheduled. They are issued in the draw phase. GrBatchToken is used
+ * to sequence the uploads relative to each other and to draws.
+ **/
+
+typedef uint64_t GrBatchToken;
+
+class GrBatchUploader : public SkRefCnt {
+public:
+    class TextureUploader;
+
+    GrBatchUploader(GrBatchToken lastUploadToken) : fLastUploadToken(lastUploadToken) {}
+    GrBatchToken lastUploadToken() const { return fLastUploadToken; }
+    virtual void upload(TextureUploader*)=0;
+
+private:
+    GrBatchToken fLastUploadToken;
+};
+
+/**
  * Base class for GrBatches that draw. These batches have a GrPipeline installed by GrDrawTarget.
  */
 class GrDrawBatch : public GrBatch {
 public:
+    class Target;
+
     GrDrawBatch();
     ~GrDrawBatch() override;
 
     virtual void getInvariantOutputColor(GrInitInvariantOutput* out) const = 0;
     virtual void getInvariantOutputCoverage(GrInitInvariantOutput* out) const = 0;
 
     const GrPipeline* pipeline() const {
         SkASSERT(fPipelineInstalled);
         return reinterpret_cast<const GrPipeline*>(fPipelineStorage.get());
     }
 
     bool installPipeline(const GrPipeline::CreateArgs&);
 
     // TODO no GrPrimitiveProcessors yet read fragment position
     bool willReadFragmentPosition() const { return false; }
 
 private:
     /**
      * initBatchTracker is a hook for the some additional overrides / optimization possibilities
      * from the GrXferProcessor.
      */
     virtual void initBatchTracker(const GrPipelineOptimizations&) = 0;
 
-    SkAlignedSTStorage<1, GrPipeline>   fPipelineStorage;
-    bool                                fPipelineInstalled;
+protected:
+    SkTArray<SkAutoTUnref<GrBatchUploader>, true>   fInlineUploads;
+
+private:
+    SkAlignedSTStorage<1, GrPipeline>               fPipelineStorage;
+    bool                                            fPipelineInstalled;
     typedef GrBatch INHERITED;
 };
 
 #endif