ubsan shift fixes

src/images/SkImageDecoder_libico.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 "SkColorPriv.h"
 #include "SkImageDecoder.h"
 #include "SkStream.h"
@@ skipping 14 matching lines @@
 private:
     typedef SkImageDecoder INHERITED;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
 //read bytes starting from the begin-th index in the buffer
 //read in Intel order, and return an integer
 
 #define readByte(buffer,begin) buffer[begin]
-#define read2Bytes(buffer,begin) buffer[begin]+(buffer[begin+1]<<8)
-#define read4Bytes(buffer,begin) buffer[begin]+(buffer[begin+1]<<8)+(buffer[begin+2]<<16)+(buffer[begin+3]<<24)
+#define read2Bytes(buffer,begin) buffer[begin]+SkLeftShift(buffer[begin+1],8)
+#define read4Bytes(buffer,begin) buffer[begin]+SkLeftShift(buffer[begin+1],8)+SkLeftShift(buffer[begin+2],16)+SkLeftShift(buffer[begin+3],24)
 
 /////////////////////////////////////////////////////////////////////////////////////////
 
 SkICOImageDecoder::SkICOImageDecoder()
 {
 }
 
 //helpers - my function pointer will call one of these, depending on the bitCount, each time through the inner loop
 static void editPixelBit1(const int pixelNo, const unsigned char* buf,
             const int xorOffset, int& x, int y, const int w,
@@ skipping 396 matching lines @@
 static SkImageDecoder_DecodeReg gReg(sk_libico_dfactory);
 
 static SkImageDecoder::Format get_format_ico(SkStreamRewindable* stream) {
     if (is_ico(stream)) {
         return SkImageDecoder::kICO_Format;
     }
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageDecoder_FormatReg gFormatReg(get_format_ico);