Minor documentation fix in base/numerics

Bug: 
Change-Id: I41728ba1b17d5020178f7adac7997cc2f0662dbc
Reviewed-on: https://chromium-review.googlesource.com/777035Reviewed-by: Justin Schuh <jschuh@chromium.org>
Commit-Queue: Justin Schuh <jschuh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517715}

base/numerics/README.md

@@ -64,7 +64,7 @@ represent the full range of the source type:
 
 ```cpp
 // Throw a compiler error if byte_value is changed to an out-of-range-type.
-int int_value = saturated_cast<int>(byte_value);
+int int_value = strict_cast<int>(byte_value);
 ```
 
 You can also enforce these compile-time restrictions on function parameters by