Switch SkAutoMalloc to SkAutoTMalloc to avoid cast

src/codec/SkCodec_libpng.cpp

Index: src/codec/SkCodec_libpng.cpp
diff --git a/src/codec/SkCodec_libpng.cpp b/src/codec/SkCodec_libpng.cpp
index 744bca41fae4d0a4b255d5681789e1af2f1c4ff4..3086a365991a70c9649761beb7d4f784ee72e722 100644
--- a/src/codec/SkCodec_libpng.cpp
+++ b/src/codec/SkCodec_libpng.cpp
@@ -14,6 +14,7 @@
 #include "SkSize.h"
 #include "SkStream.h"
 #include "SkSwizzler.h"
+#include "SkTemplates.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 // Helper macros
@@ -503,7 +504,7 @@ SkCodec::Result SkPngCodec::onGetPixels(const SkImageInfo& requestedInfo, void*
     // error?
     int row = 0;
     // This must be declared above the call to setjmp to avoid memory leaks on incomplete images.
-    SkAutoMalloc storage;
+    SkAutoTMalloc<uint8_t> storage;
     if (setjmp(png_jmpbuf(fPng_ptr))) {
         // Assume that any error that occurs while reading rows is caused by an incomplete input.
         if (fNumberPasses > 1) {
@@ -535,7 +536,7 @@ SkCodec::Result SkPngCodec::onGetPixels(const SkImageInfo& requestedInfo, void*
         const size_t srcRowBytes = width * bpp;
 
         storage.reset(width * height * bpp);
-        uint8_t* const base = static_cast<uint8_t*>(storage.get());
+        uint8_t* const base = storage.get();
 
         for (int i = 0; i < fNumberPasses; i++) {
             uint8_t* srcRow = base;
@@ -555,7 +556,7 @@ SkCodec::Result SkPngCodec::onGetPixels(const SkImageInfo& requestedInfo, void*
         }
     } else {
         storage.reset(requestedInfo.width() * SkSwizzler::BytesPerPixel(fSrcConfig));
-        uint8_t* srcRow = static_cast<uint8_t*>(storage.get());
+        uint8_t* srcRow = storage.get();
         for (; row < requestedInfo.height(); row++) {
             png_read_rows(fPng_ptr, &srcRow, png_bytepp_NULL, 1);
             // FIXME: Only call IsOpaque once, outside the loop. Same for onGetScanlines.
@@ -642,7 +643,7 @@ public:
 
         fAlphaState = kUnknown_AlphaState;
         fStorage.reset(this->getInfo().width() * SkSwizzler::BytesPerPixel(this->srcConfig()));
-        fSrcRow = static_cast<uint8_t*>(fStorage.get());
+        fSrcRow = fStorage.get();
 
         return kSuccess;
     }
@@ -696,7 +697,7 @@ public:
 
 private:
     AlphaState                  fAlphaState;
-    SkAutoMalloc                fStorage;
+    SkAutoTMalloc<uint8_t>      fStorage;
     uint8_t*                    fSrcRow;
 
     typedef SkPngCodec INHERITED;
@@ -769,8 +770,8 @@ public:
             // fail on the first pass, we can still report than some scanlines are initialized.
             return 0;
         }
-        SkAutoMalloc storage(count * fSrcRowBytes);
-        uint8_t* storagePtr = static_cast<uint8_t*>(storage.get());
+        SkAutoTMalloc<uint8_t> storage(count * fSrcRowBytes);
+        uint8_t* storagePtr = storage.get();
         uint8_t* srcRow;
         const int startRow = this->nextScanline();
         for (int i = 0; i < this->numberPasses(); i++) {