Fix silent truncations when extracting values from CheckedNumeric

base/numerics/safe_math.h

Index: base/numerics/safe_math.h
diff --git a/base/numerics/safe_math.h b/base/numerics/safe_math.h
index 78b88326c44bdf697091f4ea74232b71a434788a..6b5d4c2a99e47fe315a849752d10d78b9b0f9440 100644
--- a/base/numerics/safe_math.h
+++ b/base/numerics/safe_math.h
@@ -131,8 +131,8 @@ class CheckedNumeric {
   // template parameter, for test code, etc. However, the handler cannot access
   // the underlying value, and it is not available through other means.
   template <typename Dst = T, class CheckHandler = CheckOnFailure>
-  constexpr Dst ValueOrDie() const {
-    return IsValid<Dst>() ? state_.value()
+  constexpr StrictNumeric<Dst> ValueOrDie() const {
+    return IsValid<Dst>() ? static_cast<Dst>(state_.value())
                           : CheckHandler::template HandleFailure<Dst>();
   }
 
@@ -143,8 +143,9 @@ class CheckedNumeric {
   // parameter. WARNING: This function may fail to compile or CHECK at runtime
   // if the supplied default_value is not within range of the destination type.
   template <typename Dst = T, typename Src>
-  constexpr Dst ValueOrDefault(const Src default_value) const {
-    return IsValid<Dst>() ? state_.value() : checked_cast<Dst>(default_value);
+  constexpr StrictNumeric<Dst> ValueOrDefault(const Src default_value) const {
+    return IsValid<Dst>() ? static_cast<Dst>(state_.value())
+                          : checked_cast<Dst>(default_value);
   }
 
   // ValueFloating() - Since floating point values include their validity state,
@@ -153,7 +154,7 @@ class CheckedNumeric {
   // A range checked destination type can be supplied using the Dst template
   // parameter.
   template <typename Dst = T>
-  constexpr Dst ValueFloating() const {
+  constexpr StrictNumeric<Dst> ValueFloating() const {
     static_assert(std::numeric_limits<T>::is_iec559,
                   "Type must be floating point.");
     static_assert(std::numeric_limits<Dst>::is_iec559,