use tmp allocator for images in temp shaders

src/core/SkImagePriv.h

Index: src/core/SkImagePriv.h
diff --git a/src/core/SkImagePriv.h b/src/core/SkImagePriv.h
index ed40996acd0a1e31e5e3a547961011382df738d9..3077f343677d034994846cdb897812258bc0364c 100644
--- a/src/core/SkImagePriv.h
+++ b/src/core/SkImagePriv.h
@@ -9,19 +9,35 @@
 #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.
@@ -40,7 +56,8 @@ enum SkCopyPixelsMode {
  *  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,