Remove some LazyInstance use in base/

base/cpu.cc

Index: base/cpu.cc
diff --git a/base/cpu.cc b/base/cpu.cc
index 25328167425d4c0a242e0bfccaa47845737e81f9..8e2a621ff1f300fc2bf8691c3670410cfc0329c4 100644
--- a/base/cpu.cc
+++ b/base/cpu.cc
@@ -16,7 +16,6 @@
 
 #if defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX))
 #include "base/files/file_util.h"
-#include "base/lazy_instance.h"
 #endif
 
 #if defined(ARCH_CPU_X86_FAMILY)
@@ -130,9 +129,6 @@ class LazyCpuInfoValue {
   DISALLOW_COPY_AND_ASSIGN(LazyCpuInfoValue);
 };
 
-base::LazyInstance<LazyCpuInfoValue>::Leaky g_lazy_cpuinfo =
-    LAZY_INSTANCE_INITIALIZER;
-
 #endif  // defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) ||
         // defined(OS_LINUX))
 
@@ -221,7 +217,8 @@ void CPU::Initialize() {
     has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0;
   }
 #elif defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX))
-  cpu_brand_.assign(g_lazy_cpuinfo.Get().brand());
+  static auto lazy_cpuinfo = new LazyCpuInfoValue();

[Mark Mentovai, 2017/01/31 00:52:09]

I don’t know how much digging you want to do at each of these use sites, but it
occurs to me that in cases like this, we can simplify a little more:

// in place of class LazyCpuInfoValue
std::string CpuInfoBrandInternal();
std::string* CpuInfoBrand() {
  static std::string* value = new std::string(CpuInfoBrandInternal();
  return value;
}

  // right here
  cpu_brand_.assign(*CpuInfoBrand());

Or another thing I’ve done (I think we’ve done it together actually) has been to
get rid of the “internal” function and use a lambda.

std::string* CpuInfoBrand() {
  static std::string* value = [](){
    return new std::string(/* … */);
  }();
}

Or, in this case, since it’s only used in one place, get rid of both functions
and just put the static std::string* in one place, right here.

Different levels of improvement, and if it’s like 1,000 use sites, I don’t know
how intimate you’ll want to get with each one, but it’d be nice to not just get
rid of the legacy of LazyInstance but to also overcome design decisions that it
imposed on the code too.

+  cpu_brand_.assign(lazy_cpuinfo->brand());
 #endif
 }