Switch to one single bitmap text blob cache allocation

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAnnotation.h"
 #include "SkAutoKern.h"
@@ skipping 1687 matching lines @@
     SkASSERT(descSize == desc1->getLength());
     SkASSERT(descSize == desc2->getLength());
     desc1->computeChecksum();
     desc2->computeChecksum();
     SkASSERT(!memcmp(desc, desc1, descSize));
     SkASSERT(!memcmp(desc, desc2, descSize));
 }
 #endif
 
 /* see the note on ignoreGamma on descriptorProc */
-const SkData* SkPaint::getScalerContextDescriptor(const SkDeviceProperties* deviceProperties,
-                                                  const SkMatrix* deviceMatrix,
-                                                  bool ignoreGamma) const {
+void SkPaint::getScalerContextDescriptor(SkAutoDescriptor* ad,
+                                         const SkDeviceProperties* deviceProperties,
+                                         const SkMatrix* deviceMatrix, bool ignoreGamma) const {
     SkScalerContext::Rec    rec;
 
     SkPathEffect*   pe = this->getPathEffect();
     SkMaskFilter*   mf = this->getMaskFilter();
     SkRasterizer*   ra = this->getRasterizer();
 
     SkWriteBuffer   peBuffer, mfBuffer, raBuffer;
     size_t descSize = fill_out_rec(*this, &rec, deviceProperties, deviceMatrix, ignoreGamma,
                                    pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer);
 
-    SkASSERT(SkAlign4(descSize) == descSize);
-    SkData*             data = SkData::NewUninitialized(descSize);
-    SkDescriptor*       desc = reinterpret_cast<SkDescriptor*>(data->writable_data());
+    ad->reset(descSize);
+    SkDescriptor* desc = ad->getDesc();
 
     write_out_descriptor(desc, rec, pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer, descSize);
 
     SkASSERT(descSize == desc->getLength());
 
 #ifdef TEST_DESC
     test_desc(rec, pe, &peBuffer, mf, &mfBuffer, ra, &raBuffer, desc, descSize);
 #endif
-
-    return data;
 }
 
 /*
  *  ignoreGamma tells us that the caller just wants metrics that are unaffected
  *  by gamma correction, so we set the rec to ignore preblend: i.e. gamma = 1,
  *  contrast = 0, luminanceColor = transparent black.
  */
 void SkPaint::descriptorProc(const SkDeviceProperties* deviceProperties,
                              const SkMatrix* deviceMatrix,
                              void (*proc)(SkTypeface*, const SkDescriptor*, void*),
@@ skipping 689 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     SK_COMPILE_ASSERT(offsetof(SkPaint, fBitfields) == 10 * sizeof(void*) + 6 * sizeof(uint32_t),
                       SkPaint_notPackedTightly);
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }