Fix Windows build after 8f0636288a

Clang, GCC, and MSVS 2017 were fine with a “constexpr” definition
corresponding to a class-scope “static const” declaration, but MSVS 2015
is not.

Change-Id: I8c80c6e62d1a312bad161db98e584be225b70bbf
Reviewed-on: https://chromium-review.googlesource.com/592644
Reviewed-by: Mark Mentovai <mark@chromium.org>

minidump/minidump_writable.cc

@@ -16,8 +16,6 @@
 
 #include <stdint.h>
 
-#include <limits>
-
 #include "base/logging.h"
 #include "util/file/file_writer.h"
 #include "util/numeric/safe_assignment.h"
@@ -82,9 +80,6 @@ void MinidumpWritable::RegisterLocationDescriptor(
   registered_location_descriptors_.push_back(location_descriptor);
 }
 
-constexpr size_t MinidumpWritable::kInvalidSize =
-    std::numeric_limits<size_t>::max();
-
 MinidumpWritable::MinidumpWritable()
     : registered_rvas_(),
       registered_location_descriptors_(),

minidump/minidump_writable.h

@@ -19,6 +19,7 @@
 #include <dbghelp.h>
 #include <sys/types.h>
 
+#include <limits>
 #include <vector>
 
 #include "base/macros.h"
@@ -134,7 +135,7 @@ class MinidumpWritable {
 
   //! \brief A size value used to signal failure by methods that return
   //!     `size_t`.
-  static const size_t kInvalidSize;
+  static constexpr size_t kInvalidSize = std::numeric_limits<size_t>::max();
 
   MinidumpWritable();