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

base/sys_info.h

Index: base/sys_info.h
diff --git a/base/sys_info.h b/base/sys_info.h
index af9f017fce00099589b67a3c74580fe9b4e751d0..a125df31657f9becd0beb2312084bd729b4fa2bb 100644
--- a/base/sys_info.h
+++ b/base/sys_info.h
@@ -55,6 +55,9 @@ class BASE_EXPORT SysInfo {
   // across platforms.
   static std::string CPUArchitecture();
 
+  // Returns the CPU model name of the system.

[Mark Mentovai, 2012/09/06 14:38:14]

Document “unknown”.

Although personally I’d prefer the empty string. It’s not clear to me, but it
appears that you would already use the empty string in the case of a failure on
Windows.

[Hongbo Min, 2012/09/06 14:45:00]

Agree to use empty string directly instead of “unknown". Done

+  static std::string CPUModelName();
+
   // Return the smallest amount of memory (in bytes) which the VM system will
   // allocate.
   static size_t VMAllocationGranularity();