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diff --git a/src/gpu/GrTextureAdjuster.h b/src/gpu/GrTextureAdjuster.h
new file mode 100644
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+++ b/src/gpu/GrTextureAdjuster.h
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+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrTextureAdjuster_DEFINED
+#define GrTextureAdjuster_DEFINED
+
+#include "GrTextureProducer.h"
+#include "SkTLazy.h"
+
+/**
+ * Base class for sources that start out as textures. Optionally allows for a content area subrect.
+ * The intent is not to use content area for subrect rendering. Rather, the pixels outside the
+ * content area have undefined values and shouldn't be read *regardless* of filtering mode or
+ * the SkCanvas::SrcRectConstraint used for subrect draws.
+ */
+class GrTextureAdjuster : public GrTextureProducer {
+public:
+    /** Makes the subset of the texture safe to use with the given texture parameters.
+        outOffset will be the top-left corner of the subset if a copy is not made. Otherwise,
+        the copy will be tight to the contents and outOffset will be (0, 0). If the copy's size
+        does not match subset's dimensions then the contents are scaled to fit the copy.*/
+    GrTexture* refTextureSafeForParams(const GrSamplerParams&, SkDestinationSurfaceColorMode,
+                                       SkIPoint* outOffset);
+
+    sk_sp<GrFragmentProcessor> createFragmentProcessor(
+                                const SkMatrix& textureMatrix,
+                                const SkRect& constraintRect,
+                                FilterConstraint,
+                                bool coordsLimitedToConstraintRect,
+                                const GrSamplerParams::FilterMode* filterOrNullForBicubic,
+                                SkColorSpace* dstColorSpace,
+                                SkDestinationSurfaceColorMode) override;
+
+    // We do not ref the texture nor the colorspace, so the caller must keep them in scope while
+    // this Adjuster is alive.
+    GrTextureAdjuster(GrTexture*, SkAlphaType, const SkIRect& area, uint32_t uniqueID,
+                      SkColorSpace*);
+
+protected:
+    SkAlphaType alphaType() const override { return fAlphaType; }
+    void makeCopyKey(const CopyParams& params, GrUniqueKey* copyKey,
+                     SkDestinationSurfaceColorMode colorMode) override;
+    void didCacheCopy(const GrUniqueKey& copyKey) override;
+
+    GrTexture* originalTexture() const { return fOriginal; }
+
+    /** Returns the content area or null for the whole original texture */
+    const SkIRect* contentAreaOrNull() { return fContentArea.getMaybeNull(); }
+
+private:
+    SkTLazy<SkIRect>    fContentArea;
+    GrTexture*          fOriginal;
+    SkAlphaType         fAlphaType;
+    SkColorSpace*       fColorSpace;
+    uint32_t            fUniqueID;
+
+    GrTexture* refCopy(const CopyParams &copyParams);
+
+    typedef GrTextureProducer INHERITED;
+};
+
+#endif