Implement SysInfo::HardwareModelName() on iOS.

base/sys_info_ios.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/sys_info.h"
 
 #include <mach/mach.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <sys/sysctl.h>
@@ skipping 83 matching lines @@
 
 // static
 std::string SysInfo::CPUModelName() {
   char name[256];
   size_t len = arraysize(name);
   if (sysctlbyname("machdep.cpu.brand_string", &name, &len, NULL, 0) == 0)
     return name;
   return std::string();
 }
 
+// static
+std::string SysInfo::HardwareModelName() {
+  char model[256];
+  size_t len = sizeof(model);
+  if (sysctlbyname("hw.model", model, &len, NULL, 0) == 0)
+    return std::string(model, 0, len);

[Mark Mentovai, 2017/05/04 16:29:13]

This is weird. I don’t think that there’s a std::string constructor that accepts
(const char*, size_t, size_t). This is probably converting the char* into a
std::string and using the (const std::string&, size_t, size_t) constructor.
Yech.

You know that you have a NUL-terminated string on your hands, so
  DCHECK_GE(len, 1);  // and if you really want to, DCHECK_EQ(model[len - 1],
'\0')
  return std::string(model, len - 1);

[Alexei Svitkine (slow), 2017/05/04 16:44:07]

Good catch - done for both Mac and iOS and made CPUModelName() use the same
logic as well.

+  return std::string();
+}
+
 }  // namespace base