Flate: skia_alloc_func works on both miniz and zlib

src/core/SkFlate.cpp

Index: src/core/SkFlate.cpp
diff --git a/src/core/SkFlate.cpp b/src/core/SkFlate.cpp
index baf1c777a557b48fd0bb4b1e821af38542947f17..09975c08f72ca134639c908f714e1fb7def85be0 100644
--- a/src/core/SkFlate.cpp
+++ b/src/core/SkFlate.cpp
@@ -24,12 +24,21 @@ namespace {
 // static
 const size_t kBufferSize = 1024;
 
+// Different zlib implementations use different T.
+// We've seen size_t and unsigned.
+template <typename T> void* skia_alloc_func(void*, T items, T size) {
+    return sk_calloc_throw(SkToSizeT(items) * SkToSizeT(size));
+}
+
+static void skia_free_func(void*, void* address) { sk_free(address); }
+
 bool doFlate(bool compress, SkStream* src, SkWStream* dst) {
     uint8_t inputBuffer[kBufferSize];
     uint8_t outputBuffer[kBufferSize];
     z_stream flateData;
-    flateData.zalloc = NULL;
-    flateData.zfree = NULL;
+    flateData.zalloc = &skia_alloc_func;
+    flateData.zfree = &skia_free_func;
+    flateData.opaque = NULL;
     flateData.next_in = NULL;
     flateData.avail_in = 0;
     flateData.next_out = outputBuffer;
@@ -170,9 +179,9 @@ SkDeflateWStream::SkDeflateWStream(SkWStream* out)
     if (!fImpl->fOut) {
         return;
     }
-    fImpl->fZStream.zalloc = Z_NULL;
-    fImpl->fZStream.zfree = Z_NULL;
-    fImpl->fZStream.opaque = Z_NULL;
+    fImpl->fZStream.zalloc = &skia_alloc_func;
+    fImpl->fZStream.zfree = &skia_free_func;
+    fImpl->fZStream.opaque = NULL;
     SkDEBUGCODE(int r =) deflateInit(&fImpl->fZStream, Z_DEFAULT_COMPRESSION);
     SkASSERT(Z_OK == r);
 }