add safemath version of readbuffer->skip

Bug: skia:
Change-Id: I6a5d24569cc1bd93bd190d81e3375993da9c56f0
Reviewed-on: https://skia-review.googlesource.com/88581
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/src/core/SkMath.cpp b/src/core/SkMath.cpp
index 6eff790c85..58645dab8f 100644
--- a/src/core/SkMath.cpp
+++ b/src/core/SkMath.cpp
@@ -9,6 +9,7 @@
 #include "SkFixed.h"
 #include "SkFloatBits.h"
 #include "SkFloatingPoint.h"
+#include "SkSafeMath.h"
 #include "SkScalar.h"
 
 #define sub_shift(zeros, x, n)  \
@@ -67,8 +68,6 @@ int32_t SkSqrtBits(int32_t x, int count) {
     return root;
 }
 
-///////////////////////////////////////////////////////////////////////////////
-
 float SkScalarSinCos(float radians, float* cosValue) {
     float sinValue = sk_float_sin(radians);
 
@@ -84,3 +83,17 @@ float SkScalarSinCos(float radians, float* cosValue) {
     }
     return sinValue;
 }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+size_t SkSafeMath::Add(size_t x, size_t y) {
+    SkSafeMath tmp;
+    size_t sum = tmp.add(x, y);
+    return tmp.ok() ? sum : SK_MaxSizeT;
+}
+
+size_t SkSafeMath::Mul(size_t x, size_t y) {
+    SkSafeMath tmp;
+    size_t prod = tmp.mul(x, y);
+    return tmp.ok() ? prod : SK_MaxSizeT;
+}