Revert of Consolidate GPU buffer implementations

src/gpu/batches/GrAAStrokeRectBatch.cpp

Index: src/gpu/batches/GrAAStrokeRectBatch.cpp
diff --git a/src/gpu/batches/GrAAStrokeRectBatch.cpp b/src/gpu/batches/GrAAStrokeRectBatch.cpp
index 2ce5eca7a6b4e2244f842f084f4ca73e37d36c52..54bc495a4d94e63339877461555023bdd719e190 100644
--- a/src/gpu/batches/GrAAStrokeRectBatch.cpp
+++ b/src/gpu/batches/GrAAStrokeRectBatch.cpp
@@ -123,7 +123,8 @@
     static const int kBevelVertexCnt = 24;
     static const int kNumBevelRectsInIndexBuffer = 256;
 
-    static const GrBuffer* GetIndexBuffer(GrResourceProvider* resourceProvider, bool miterStroke);
+    static const GrIndexBuffer* GetIndexBuffer(GrResourceProvider* resourceProvider,
+                                               bool miterStroke);
 
     GrColor color() const { return fBatch.fColor; }
     bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
@@ -205,7 +206,7 @@
     int indicesPerInstance = this->miterStroke() ? kMiterIndexCnt : kBevelIndexCnt;
     int instanceCount = fGeoData.count();
 
-    const SkAutoTUnref<const GrBuffer> indexBuffer(
+    const SkAutoTUnref<const GrIndexBuffer> indexBuffer(
         GetIndexBuffer(target->resourceProvider(), this->miterStroke()));
     InstancedHelper helper;
     void* vertices = helper.init(target, kTriangles_GrPrimitiveType, vertexStride,
@@ -234,8 +235,8 @@
     helper.recordDraw(target);
 }
 
-const GrBuffer* AAStrokeRectBatch::GetIndexBuffer(GrResourceProvider* resourceProvider,
-                                                  bool miterStroke) {
+const GrIndexBuffer* AAStrokeRectBatch::GetIndexBuffer(GrResourceProvider* resourceProvider,
+                                                       bool miterStroke) {
 
     if (miterStroke) {
         static const uint16_t gMiterIndices[] = {