cc: Handle overflow/underflow in MathUtil::RoundUp/RoundDown functions.

cc/resources/resource_util.h

Index: cc/resources/resource_util.h
diff --git a/cc/resources/resource_util.h b/cc/resources/resource_util.h
index 0953fbbdb1b33919e7d78c44dc57cc138ca6f84d..9d9905b47d5d8644a20472fd08eab8da2913ca21 100644
--- a/cc/resources/resource_util.h
+++ b/cc/resources/resource_util.h
@@ -68,9 +68,6 @@ class CC_EXPORT ResourceUtil {
   static inline void VerifyType();
 
   template <typename T>
-  static bool VerifyRoundUp(T value, T round_up);
-
-  template <typename T>
   static bool VerifyFitsInBytesInternal(int width,
                                         int height,
                                         ResourceFormat format,
@@ -107,10 +104,7 @@ T ResourceUtil::CheckedWidthInBytes(int width, ResourceFormat format) {
   DCHECK(VerifyFitsInBytesInternal<T>(width, 0, format, false, false));
   base::CheckedNumeric<T> checked_value = BitsPerPixel(format);
   checked_value *= width;
-  // TODO(prashant.n): Move the value roundup overflow to MathUtil class.
-  // http://crbug.com/515566
-  CHECK(VerifyRoundUp(checked_value.ValueOrDie(), static_cast<T>(8)));
-  checked_value = MathUtil::RoundUp<T>(checked_value.ValueOrDie(), 8);
+  checked_value = MathUtil::CheckedRoundUp<T>(checked_value.ValueOrDie(), 8);
   checked_value /= 8;
   return checked_value.ValueOrDie();
 }
@@ -123,8 +117,7 @@ T ResourceUtil::CheckedSizeInBytes(const gfx::Size& size,
                                       false));
   base::CheckedNumeric<T> checked_value = BitsPerPixel(format);
   checked_value *= size.width();
-  CHECK(VerifyRoundUp(checked_value.ValueOrDie(), static_cast<T>(8)));
-  checked_value = MathUtil::RoundUp<T>(checked_value.ValueOrDie(), 8);
+  checked_value = MathUtil::CheckedRoundUp<T>(checked_value.ValueOrDie(), 8);
   checked_value /= 8;
   checked_value *= size.height();
   return checked_value.ValueOrDie();
@@ -170,18 +163,6 @@ void ResourceUtil::VerifyType() {
 }
 
 template <typename T>
-bool ResourceUtil::VerifyRoundUp(T value, T round_up) {
-  if (round_up == 0)
-    return false;
-  if (value == round_up)
-    return true;
-  if ((std::numeric_limits<T>::max() - (value - (value % round_up))) >=
-      round_up)
-    return true;
-  return false;
-}
-
-template <typename T>
 bool ResourceUtil::VerifyFitsInBytesInternal(int width,
                                              int height,
                                              ResourceFormat format,
@@ -194,8 +175,7 @@ bool ResourceUtil::VerifyFitsInBytesInternal(int width,
 
   // Roundup bits to byte (8 bits) boundary. If width is 3 and BitsPerPixel is
   // 4, then it should return 16, so that row pixels do not get truncated.
-  DCHECK(VerifyRoundUp(checked_value.ValueOrDie(), static_cast<T>(8)));
-  checked_value = MathUtil::RoundUp<T>(checked_value.ValueOrDie(), 8);
+  checked_value = MathUtil::UncheckedRoundUp<T>(checked_value.ValueOrDie(), 8);
 
   // If aligned is true, bytes are aligned on 4-bytes boundaries for upload
   // performance, assuming that GL_PACK_ALIGNMENT or GL_UNPACK_ALIGNMENT have
@@ -204,7 +184,8 @@ bool ResourceUtil::VerifyFitsInBytesInternal(int width,
     checked_value /= 8;
     if (!checked_value.IsValid())
       return false;
-    checked_value = MathUtil::RoundUp<T>(checked_value.ValueOrDie(), 4);
+    checked_value =
+        MathUtil::UncheckedRoundUp<T>(checked_value.ValueOrDie(), 4);
     checked_value *= 8;
   }
 
@@ -226,11 +207,10 @@ T ResourceUtil::BytesInternal(int width,
                               bool aligned) {
   T bytes = BitsPerPixel(format);
   bytes *= width;
-  DCHECK(VerifyRoundUp(bytes, static_cast<T>(8)));
-  bytes = MathUtil::RoundUp<T>(bytes, 8);
+  bytes = MathUtil::UncheckedRoundUp<T>(bytes, 8);
   bytes /= 8;
   if (aligned)
-    bytes = MathUtil::RoundUp<T>(bytes, 4);
+    bytes = MathUtil::UncheckedRoundUp<T>(bytes, 4);
   if (verify_size)
     bytes *= height;