Update the generator to work around a MSVC limitation.

mojo/public/tools/bindings/generators/mojom_cpp_generator.py

Index: mojo/public/tools/bindings/generators/mojom_cpp_generator.py
diff --git a/mojo/public/tools/bindings/generators/mojom_cpp_generator.py b/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
index a2618a47514f6719158775c72743fac3904f5e0a..34bba30e69be34948f5bd666dc76fbfc94388e61 100644
--- a/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
+++ b/mojo/public/tools/bindings/generators/mojom_cpp_generator.py
@@ -254,6 +254,21 @@ def TranslateConstants(token, kind):
   if (kind is not None and mojom.IsFloatKind(kind)):
       return token if token.isdigit() else token + "f";
 
+  # Per C++11, 2.14.2, the type of an integer literal is the first of the
+  # corresponding list in Table 6 in which its value can be represented. In this
+  # case, the list for decimal constants with no suffix is:
+  #   int, long int, long long int
+  # The standard considers a program ill-formed if it contains an integer
+  # literal that cannot be represented by any of the allowed types.
+  #
+  # As it turns out, MSVC doesn't bother trying to fall back to long long int,
+  # so the integral constant -2147483648 causes it grief: it decides to
+  # represent 2147483648 as an unsigned integer, and then warns that the unary
+  # minus operator doesn't make sense on unsigned types. Doh!
+  if kind == mojom.INT32 and token == '-2147483648':
+    return '(-%d - 1) /* %s */' % (
+        2**31 - 1, 'Workaround for MSVC bug; see https://crbug.com/445618')
+
   return '%s%s' % (token, _kind_to_cpp_literal_suffix.get(kind, ''))
 
 def ExpressionToText(value, kind=None):