Misc truncation fixes for gn builds with VS 2015

chrome/test/chromedriver/util.cc

Index: chrome/test/chromedriver/util.cc
diff --git a/chrome/test/chromedriver/util.cc b/chrome/test/chromedriver/util.cc
index d0d241699a9dac6bb923fba84cd6dec3d126c0fb..b0c84b83d57d40ae3b00c4444994429c015c81f6 100644
--- a/chrome/test/chromedriver/util.cc
+++ b/chrome/test/chromedriver/util.cc
@@ -304,8 +304,8 @@ struct ZipEntry {
     stream.WriteUInt32(crc);
     stream.WriteUInt32(compressed_data.length());
     stream.WriteUInt32(uncompressed_size);
-    stream.WriteUInt16(name.length());
-    stream.WriteUInt16(fields.length());
+    stream.WriteUInt16(base::checked_cast<uint16>(name.length()));
+    stream.WriteUInt16(base::checked_cast<uint16>(fields.length()));
     stream.WriteString(name);
     stream.WriteString(fields);
     stream.WriteString(compressed_data);
@@ -322,8 +322,8 @@ struct ZipEntry {
     stream.WriteUInt32(crc);
     stream.WriteUInt32(compressed_data.length());
     stream.WriteUInt32(uncompressed_size);
-    stream.WriteUInt16(name.length());
-    stream.WriteUInt16(fields.length());
+    stream.WriteUInt16(base::checked_cast<uint16>(name.length()));
+    stream.WriteUInt16(base::checked_cast<uint16>(fields.length()));
     stream.WriteUInt16(0);  // Comment length.
     stream.WriteUInt16(0);  // Disk number where file starts.
     stream.WriteUInt16(0);  // Internal file attr.