Add a GrPathRange class

src/gpu/GrPathRange.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrPathRange_DEFINED
+#define GrPathRange_DEFINED
+
+#include "GrGpuObject.h"
+#include "GrResourceCache.h"
+#include "SkStrokeRec.h"
+
+class SkPath;
+
+/**
+ * Represents a contiguous range of GPU path objects with a common stroke. The
+ * path range is immutable with the exception that individual paths can be
+ * initialized lazily. Unititialized paths are silently ignored by drawing
+ * functions.
+ */
+class GrPathRange : public GrGpuObject {
+public:
+    SK_DECLARE_INST_COUNT(GrPathRange);
+
+    static const bool kIsWrapped = false;
+
+    static GrResourceKey::ResourceType resourceType() {
+        static const GrResourceKey::ResourceType type = GrResourceKey::GenerateResourceType();
+        return type;
+    }
+
+    /**
+     * Initialize to a range with a fixed size and stroke. Stroke must not be hairline.
+     */
+    GrPathRange(GrGpu* gpu, size_t size, const SkStrokeRec& stroke)
+        : INHERITED(gpu, kIsWrapped),
+          fSize(size),
+          fStroke(stroke) {
+    }
+
+    size_t getSize() const { return fSize; }
+    const SkStrokeRec& getStroke() const { return fStroke; }
+
+    /**
+     * Initialize a path in the range. It is invalid to call this method for a
+     * path that has already been initialized.
+     */
+    virtual void initAt(size_t index, const SkPath&) = 0;
+
+protected:
+    size_t fSize;
+    SkStrokeRec fStroke;
+
+private:
+    typedef GrGpuObject INHERITED;
+};
+
+#endif