Fix silent truncations when extracting values from CheckedNumeric

chrome/utility/safe_browsing/mac/hfs.cc

Index: chrome/utility/safe_browsing/mac/hfs.cc
diff --git a/chrome/utility/safe_browsing/mac/hfs.cc b/chrome/utility/safe_browsing/mac/hfs.cc
index fd2f75337e4e239a29a30ddde7509723bee0026c..ce1b69c209e5ffd396620320b807c857de37e337 100644
--- a/chrome/utility/safe_browsing/mac/hfs.cc
+++ b/chrome/utility/safe_browsing/mac/hfs.cc
@@ -383,12 +383,12 @@ bool HFSForkReadStream::Read(uint8_t* buffer,
       read_current_extent_ = true;
     }
 
-    size_t extent_offset = fork_logical_offset_ % extent_size.ValueOrDie();
-    size_t bytes_to_copy =
-        std::min(std::min(static_cast<size_t>(fork_.logicalSize) -
-                              fork_logical_offset_,
-                          extent_size.ValueOrDie() - extent_offset),
-                 buffer_space_remaining);
+    size_t extent_offset = (fork_logical_offset_ % extent_size).ValueOrDie();
+    size_t bytes_to_copy = std::min(
+        std::min(
+            static_cast<size_t>(fork_.logicalSize) - fork_logical_offset_,
+            static_cast<size_t>((extent_size - extent_offset).ValueOrDie())),
+        buffer_space_remaining);
 
     memcpy(&buffer[buffer_size - buffer_space_remaining],
            &current_extent_data_[extent_offset],