Add parser for new cpu freq file

chrome/browser/chromeos/power/cpu_data_collector.h

Index: chrome/browser/chromeos/power/cpu_data_collector.h
diff --git a/chrome/browser/chromeos/power/cpu_data_collector.h b/chrome/browser/chromeos/power/cpu_data_collector.h
index c9b4bcb849d6b87f9aabc9dbfa2ae48f85aeddae..184cd8bf1ff188c4529ee84a9d37c05568131441 100644
--- a/chrome/browser/chromeos/power/cpu_data_collector.h
+++ b/chrome/browser/chromeos/power/cpu_data_collector.h
@@ -71,6 +71,64 @@ class CpuDataCollector {
   // CPU state occupancy samples.
   void Start();
 
+  // Samples the CPU idle state information from sysfs. |cpu_count| is the
+  // number of possible CPUs on the system. Sample at index i in |idle_samples|
+  // corresponds to the idle state information of the i-th CPU.
+  static void SampleCpuIdleData(

[Daniel Erat, 2017/05/02 23:41:10]

only the methods that you're actually calling from tests need to be public
static methods. everything else should only be declared in the .cc file as
before.

[weidongg, 2017/05/03 21:32:31]

Done.

+      int cpu_count,
+      std::vector<std::string>* cpu_idle_state_names,
+      std::vector<CpuDataCollector::StateOccupancySample>* idle_samples);
+
+  // Read CPU frequency data of a specific CPU from the file in |path| and fill
+  // |cpu_freq_state_names| and |freq_sample| with the data.
+  // Sample file looks like:
+  // 126000 223344
+  // 216000 93495
+  // ...
+  // 1800000 321907
+  static bool ReadCpuFreqTimeInState(
+      const std::string& path,
+      std::vector<std::string>* cpu_freq_state_names,
+      CpuDataCollector::StateOccupancySample* freq_sample);
+
+  // Read CPU frequency data of all CPUs from the file in |path| and fill
+  // |cpu_freq_state_names| and |freq_samples| with the data. |cpu_count| is the
+  // number of possible CPUs on the system. Note that |freq_samples| is not
+  // empty and sample at index i in |freq_samples| corresponds to the freq state
+  // information of the i-th CPU. |cpu_online| of each sample must be set before
+  // calling this function.
+  // Sample file looks like:
+  // freq   cpu0    cpu1
+  // 126000   223344    223311
+  // 216000   93495   93450
+  // ...
+  // 1800000    321907    331897
+  static bool ReadCpuFreqAllTimeInState(
+      int cpu_count,
+      const std::string& path,
+      std::vector<std::string>* cpu_freq_state_names,
+      std::vector<CpuDataCollector::StateOccupancySample>* freq_samples);
+
+  // Samples the CPU freq state information from sysfs. |cpu_count| is the
+  // number of possible CPUs on the system. Sample at index i in |freq_samples|
+  // corresponds to the freq state information of the i-th CPU.
+  static void SampleCpuFreqData(

[Daniel Erat, 2017/05/02 23:41:10]

see above

[weidongg, 2017/05/03 21:32:31]

Done.

+      int cpu_count,
+      std::vector<std::string>* cpu_freq_state_names,
+      std::vector<CpuDataCollector::StateOccupancySample>* freq_samples);
+
+  // Samples CPU idle and CPU freq data from sysfs. This function should run on
+  // the blocking pool as reading from sysfs is a blocking task. Elements at
+  // index i in |idle_samples| and |freq_samples| correspond to the idle and
+  // freq samples of CPU i. This also function reads the number of CPUs from
+  // sysfs if *|cpu_count| < 0.
+  static void SampleCpuStateAsync(

[Daniel Erat, 2017/05/02 23:41:10]

see above

[weidongg, 2017/05/03 21:32:31]

Done.

+      int* cpu_count,
+      std::vector<std::string>* cpu_idle_state_names,
+      std::vector<CpuDataCollector::StateOccupancySample>* idle_samples,
+      std::vector<std::string>* cpu_freq_state_names,
+      std::vector<CpuDataCollector::StateOccupancySample>* freq_samples);
+
  private:
   // Posts callbacks to the blocking pool which collect CPU state occupancy
   // samples from the sysfs.