Always make SkImageShaders in heap.

I made a couple of measurments, and it looks like any differences is
well below the noise threshold.

Just for the record run1: .9991 of baseline and run2 .9988 of baseline.
I was using top25 .skps as workload.

TBR=mtklein@google.com

Change-Id: If4fa06e5d5df72fb67dbb4bbb99c926f05765897
Reviewed-on: https://skia-review.googlesource.com/8341
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Herb Derby <herb@google.com>

4 files changed, 7 insertions, 26 deletions

diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index 2b5c37fa2e..45ec2b70ae 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -334,15 +334,13 @@ void SkBitmapDevice::drawBitmapRect(const SkDraw& draw, const SkBitmap& bitmap,
     // Since the shader need only live for our stack-frame, pass in a custom allocator. This
     // can save malloc calls, and signals to SkMakeBitmapShader to not try to copy the bitmap
     // if its mutable, since that precaution is not needed (give the short lifetime of the shader).
-    SkTBlitterAllocator allocator;
+
     // construct a shader, so we can call drawRect with the dst
     auto s = SkMakeBitmapShader(*bitmapPtr, SkShader::kClamp_TileMode, SkShader::kClamp_TileMode,
-                                &matrix, kNever_SkCopyPixelsMode, &allocator);
+                                &matrix, kNever_SkCopyPixelsMode);
     if (!s) {
         return;
     }
-    // we deliberately add a ref, since the allocator wants to be the last owner
-    s.get()->ref();
 
     SkPaint paintWithShader(paint);
     paintWithShader.setStyle(SkPaint::kFill_Style);
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 4308000457..4d1c5a4998 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -85,23 +85,10 @@ public:
     SkAutoBitmapShaderInstall(const SkBitmap& src, const SkPaint& paint,
                               const SkMatrix* localMatrix = nullptr)
             : fPaint(paint) /* makes a copy of the paint */ {
-        // TODO(herb): Move this over to SkArenaAlloc when arena alloc has a
-        // facility to return sk_sps.
+
         fPaint.setShader(SkMakeBitmapShader(src, SkShader::kClamp_TileMode,
                                             SkShader::kClamp_TileMode, localMatrix,
-                                            kNever_SkCopyPixelsMode,
-                                            &fAllocator));
-        // we deliberately left the shader with an owner-count of 2
-        fPaint.getShader()->ref();
-        SkASSERT(2 == fPaint.getShader()->getRefCnt());
-    }
-
-    ~SkAutoBitmapShaderInstall() {
-        // since fAllocator will destroy shader, we insist that owners == 2
-        SkASSERT(2 == fPaint.getShader()->getRefCnt());
-
-        fPaint.setShader(nullptr); // unref the shader by 1
-
+                                            kNever_SkCopyPixelsMode));
     }
 
     // return the new paint that has the shader applied
@@ -110,8 +97,6 @@ public:
 private:
     // copy of caller's paint (which we then modify)
     SkPaint             fPaint;
-    // Stores the shader.
-    SkTBlitterAllocator fAllocator;
 };
 #define SkAutoBitmapShaderInstall(...) SK_REQUIRE_LOCAL_VAR(SkAutoBitmapShaderInstall)
 
diff --git a/src/core/SkImagePriv.h b/src/core/SkImagePriv.h
index 601108665d..d6e58d3c11 100644
--- a/src/core/SkImagePriv.h
+++ b/src/core/SkImagePriv.h
@@ -30,8 +30,7 @@ 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);
+                                   const SkMatrix* localMatrix, SkCopyPixelsMode);
 
 /**
  *  Examines the bitmap to decide if it can share the existing pixelRef, or
@@ -51,8 +50,7 @@ sk_sp<SkShader> SkMakeBitmapShader(const SkBitmap& src, SkShader::TileMode, SkSh
  *  SkImageInfo, or the bitmap's pixels cannot be accessed, this will return
  *  nullptr.
  */
-extern sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap&, SkCopyPixelsMode,
-                                                  SkTBlitterAllocator* = nullptr);
+extern sk_sp<SkImage> SkMakeImageFromRasterBitmap(const SkBitmap&, SkCopyPixelsMode);
 
 // 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,
diff --git a/src/core/SkShader.cpp b/src/core/SkShader.cpp
index 81aae116d5..cfdd8b946e 100644
--- a/src/core/SkShader.cpp
+++ b/src/core/SkShader.cpp
@@ -232,7 +232,7 @@ sk_sp<SkShader> SkShader::MakeBitmapShader(const SkBitmap& src, TileMode tmx, Ti
     if (localMatrix && !localMatrix->invert(nullptr)) {
         return nullptr;
     }
-    return SkMakeBitmapShader(src, tmx, tmy, localMatrix, kIfMutable_SkCopyPixelsMode, nullptr);
+    return SkMakeBitmapShader(src, tmx, tmy, localMatrix, kIfMutable_SkCopyPixelsMode);
 }
 
 sk_sp<SkShader> SkShader::MakePictureShader(sk_sp<SkPicture> src, TileMode tmx, TileMode tmy,