Let blitters be notified when they're done being used

src/core/SkBlitter.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 "SkBlitter.h"
 #include "SkAntiRun.h"
 #include "SkColor.h"
 #include "SkColorFilter.h"
 #include "SkCoreBlitters.h"
 #include "SkFilterShader.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
 #include "SkMask.h"
 #include "SkMaskFilter.h"
 #include "SkString.h"
 #include "SkTLazy.h"
 #include "SkUtils.h"
 #include "SkXfermode.h"
 
-SkBlitter::~SkBlitter() {}
+SkBlitter::~SkBlitter() {
+    if (NULL != fBlitMemory) {
+        sk_free(fBlitMemory);
+        fBlitMemory = NULL;
+    }
+}
 
 bool SkBlitter::isNullBlitter() const { return false; }
 
 bool SkBlitter::resetShaderContext(const SkShader::ContextRec&) {
     return true;
 }
 
 SkShader::Context* SkBlitter::getShaderContext() const {
     return NULL;
 }
@@ skipping 152 matching lines @@
         int height = clip.height();
         int y = clip.fTop;
         while (--height >= 0) {
             this->blitAntiH(clip.fLeft, y, aa, runs);
             aa += mask.fRowBytes;
             y += 1;
         }
     }
 }
 
+void* SkBlitter::allocBlitMemory(size_t sz) {
+    SkASSERT(NULL == fBlitMemory);
+    if (NULL != fBlitMemory) {
+        sk_free(fBlitMemory);
+        fBlitMemory = NULL;
+    }
+
+    fBlitMemory = sk_malloc_throw(sz);
+    return fBlitMemory;
+}
+
 /////////////////////// these guys are not virtual, just a helpers
 
 void SkBlitter::blitMaskRegion(const SkMask& mask, const SkRegion& clip) {
     if (clip.quickReject(mask.fBounds)) {
         return;
     }
 
     SkRegion::Cliperator clipper(clip, mask.fBounds);
 
     while (!clipper.done()) {
@@ skipping 826 matching lines @@
     fShaderContext->~Context();
     SkShader::Context* ctx = fShader->createContext(rec, (void*)fShaderContext);
     if (NULL == ctx) {
         // Need a valid context in fShaderContext's storage, so we can later (or our caller) call
         // the in-place destructor.
         SkNEW_PLACEMENT_ARGS(fShaderContext, SkTransparentShaderContext, (*fShader, rec));
         return false;
     }
     return true;
 }