use tmp allocator for images in temp shaders

src/core/SkImagePriv.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImagePriv_DEFINED
 #define SkImagePriv_DEFINED
 
 #include "SkImage.h"
+#include "SkSmallAllocator.h"
 #include "SkSurface.h"
 
-// Call this if you explicitly want to use/share this pixelRef in the image
-extern sk_sp<SkImage> SkMakeImageFromPixelRef(const SkImageInfo&, SkPixelRef*,
-                                              const SkIPoint& pixelRefOrigin,
-                                              size_t rowBytes);
-
 enum SkCopyPixelsMode {
     kIfMutable_SkCopyPixelsMode,  //!< only copy src pixels if they are marked mutable
     kAlways_SkCopyPixelsMode,     //!< always copy src pixels (even if they are marked immutable)
     kNever_SkCopyPixelsMode,      //!< never copy src pixels (even if they are marked mutable)
 };
 
+enum {kSkBlitterContextSize = 3332};
+
+// Commonly used allocator. It currently is only used to allocate up to 3 objects. The total
+// bytes requested is calculated using one of our large shaders, its context size plus the size of
+// an Sk3DBlitter in SkDraw.cpp
+// Note that some contexts may contain other contexts (e.g. for compose shaders), but we've not
+// yet found a situation where the size below isn't big enough.
+typedef SkSmallAllocator<3, kSkBlitterContextSize> SkTBlitterAllocator;
+
+// If alloc is non-nullptr, it will be used to allocate the returned SkShader, and MUST outlive
+// the SkShader.
+sk_sp<SkShader> SkMakeBitmapShader(const SkBitmap& src, SkShader::TileMode, SkShader::TileMode,
+                                   const SkMatrix* localMatrix, SkCopyPixelsMode,
+                                   SkTBlitterAllocator* alloc);
+
+// Call this if you explicitly want to use/share this pixelRef in the image
+extern sk_sp<SkImage> SkMakeImageFromPixelRef(const SkImageInfo&, SkPixelRef*,
+                                              const SkIPoint& pixelRefOrigin,
+                                              size_t rowBytes);
+
 /**
  *  Examines the bitmap to decide if it can share the existing pixelRef, or
  *  if it needs to make a deep-copy of the pixels.
  *
  *  The bitmap's pixelref will be shared if either the bitmap is marked as
  *  immutable, or CopyPixelsMode allows it. Shared pixel refs are also
  *  locked when kLocked_SharedPixelRefMode is specified.
  *
  *  Passing kLocked_SharedPixelRefMode allows the image's peekPixels() method
  *  to succeed, but it will force any lazy decodes/generators to execute if
  *  they exist on the pixelref.
  *
  *  It is illegal to call this with a texture-backed bitmap.
  *
  *  If the bitmap's colortype cannot be converted into a corresponding
  *  SkImageInfo, or the bitmap's pixels cannot be accessed, this will return
  *  nullptr.
  */
-extern sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap&, SkCopyPixelsMode);
+extern sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap&, SkCopyPixelsMode,
+                                                  SkTBlitterAllocator* = nullptr);
 
 // Given an image created from SkNewImageFromBitmap, return its pixelref. This
 // may be called to see if the surface and the image share the same pixelref,
 // in which case the surface may need to perform a copy-on-write.
 extern const SkPixelRef* SkBitmapImageGetPixelRef(const SkImage* rasterImage);
 
 // When a texture is shared by a surface and an image its budgeted status is that of the
 // surface. This function is used when the surface makes a new texture for itself in order
 // for the orphaned image to determine whether the original texture counts against the
 // budget or not.
 extern void SkTextureImageApplyBudgetedDecision(SkImage* textureImage);
 
 // Update the texture wrapped by an image created with NewTexture. This
 // is called when a surface and image share the same GrTexture and the
 // surface needs to perform a copy-on-write
 extern void SkTextureImageSetTexture(SkImage* image, GrTexture* texture);
 
 GrTexture* GrDeepCopyTexture(GrTexture* src, SkBudgeted);
 
 #endif