Refine systemInfo.cpu API defintions and provide systemInfo.cpu.get impl for Windows and Linux

base/sys_info_mac.cc

Index: base/sys_info_mac.cc
diff --git a/base/sys_info_mac.cc b/base/sys_info_mac.cc
index 1a1d23c236f6856ebb55157a0dcd56706ca4d6ef..3a936890342b94d37ddccdad1d5f19ecfe28785a 100644
--- a/base/sys_info_mac.cc
+++ b/base/sys_info_mac.cc
@@ -8,6 +8,8 @@
 #include <CoreServices/CoreServices.h>
 #include <mach/mach_host.h>
 #include <mach/mach_init.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
@@ -54,4 +56,13 @@ int64 SysInfo::AmountOfPhysicalMemory() {
   return static_cast<int64>(hostinfo.max_mem);
 }
 
+// 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();
+}
+
 }  // namespace base