extensions: Add CPU temperatures field to system.cpu.getInfo() function

extensions/browser/api/system_cpu/system_cpu_apitest.cc

Index: extensions/browser/api/system_cpu/system_cpu_apitest.cc
diff --git a/extensions/browser/api/system_cpu/system_cpu_apitest.cc b/extensions/browser/api/system_cpu/system_cpu_apitest.cc
index eabacff9393df97dbea45bf326e9ab95bf9df720..8e0bdef39ae14b58b9b8386a7e23939c1a880f1c 100644
--- a/extensions/browser/api/system_cpu/system_cpu_apitest.cc
+++ b/extensions/browser/api/system_cpu/system_cpu_apitest.cc
@@ -28,6 +28,12 @@ class MockCpuInfoProviderImpl : public CpuInfoProvider {
     info_.processors[0].usage.user = 2;
     info_.processors[0].usage.idle = 3;
     info_.processors[0].usage.total = 6;
+
+    info_.temperatures.clear();

[tbarzic, 2017/04/27 17:50:19]

info_.temperatures = {30.125, 40.0625};?

[Simon Que, 2017/04/27 17:59:54]

Done.

+    // The fractional part of these values should be exactly represented as
+    // floating points to avoid rounding errors.
+    info_.temperatures.push_back(30.125);
+    info_.temperatures.push_back(40.0625);
     return true;
   }