Adding immediate mode draw target for debug

src/gpu/GrImmediateDrawTarget.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 GrImmediateDrawTarget_DEFINED
+#define GrImmediateDrawTarget_DEFINED
+
+#include "GrDrawTarget.h"
+
+#include "GrBatchTarget.h"
+
+/**
+ * A debug GrDrawTarget which immediately flushes every command it receives
+ */
+class GrImmediateDrawTarget : public GrClipTarget {
+public:
+
+    /**
+     * Creates a GrImmediateDrawTarget
+     *
+     * @param context    the context object that owns this draw buffer.
+     */
+    GrImmediateDrawTarget(GrContext* context);
+
+    ~GrImmediateDrawTarget() override;
+
+    // tracking for draws
+    DrawToken getCurrentDrawToken() override { return DrawToken(this, fDrawID); }
+
+    void clearStencilClip(const SkIRect& rect,
+                          bool insideClip,
+                          GrRenderTarget* renderTarget) override;
+
+    void discard(GrRenderTarget*) override;
+
+private:
+    void onReset() override;
+    void onFlush() override;
+
+    // overrides from GrDrawTarget
+    void onDrawBatch(GrBatch*, const PipelineInfo&) override;
+    void onStencilPath(const GrPipelineBuilder&,
+                       const GrPathProcessor*,
+                       const GrPath*,
+                       const GrScissorState&,
+                       const GrStencilSettings&) override {
+        SkFAIL("Only batch implemented\n");
+    }
+    void onDrawPath(const GrPathProcessor*,
+                    const GrPath*,
+                    const GrStencilSettings&,
+                    const PipelineInfo&) override {
+        SkFAIL("Only batch implemented\n");
+    }
+    void onDrawPaths(const GrPathProcessor*,
+                     const GrPathRange*,
+                     const void* indices,
+                     PathIndexType,
+                     const float transformValues[],
+                     PathTransformType,
+                     int count,
+                     const GrStencilSettings&,
+                     const PipelineInfo&) override {
+        SkFAIL("Only batch implemented\n");
+    }
+    void onClear(const SkIRect* rect,
+                 GrColor color,
+                 bool canIgnoreRect,
+                 GrRenderTarget* renderTarget) override;
+    void onCopySurface(GrSurface* dst,
+                       GrSurface* src,
+                       const SkIRect& srcRect,
+                       const SkIPoint& dstPoint) override;
+
+    bool isIssued(uint32_t drawID) override { return drawID != fDrawID; }
+
+    bool SK_WARN_UNUSED_RESULT setupPipelineAndShouldDraw(GrPipeline*,
+                                                          const GrDrawTarget::PipelineInfo&);
+
+    void recordXferBarrierIfNecessary(const GrPipeline*);
+
+    GrBatchTarget fBatchTarget;
+    uint32_t fDrawID;
+
+    typedef GrClipTarget INHERITED;
+};
+
+#endif