Cherry pick PR #4155: Fallback to 100 ticks per second for CPU usage … (

#4442)

Fix CPU usage measurement when getting the clock ticks per second
reading failed (e.g. Android).

Refer to the original PR: #4155

b/341774149

Co-authored-by: cobalt-github-releaser-bot <[email protected]>
Co-authored-by: aee <[email protected]>

cobalt/base/process/process_metrics_helper.cc

@@ -64,7 +64,8 @@ double CalculateCPUUsageSeconds(const std::string& utime_string,
 
 // static
 int ProcessMetricsHelper::GetClockTicksPerS() {
-  return clock_ticks_per_s.load();
+  int result = clock_ticks_per_s.load();
+  return result > 0 ? result : 100;
 }
 
 // static
@@ -104,15 +105,12 @@ void ProcessMetricsHelper::PopulateClockTicksPerS() {
 
 // static
 TimeDelta ProcessMetricsHelper::GetCumulativeCPUUsage() {
-  int ticks_per_s = clock_ticks_per_s.load();
-  if (ticks_per_s == 0) return TimeDelta();
-  return GetCPUUsage(FilePath("/proc/self"), ticks_per_s);
+  return GetCPUUsage(FilePath("/proc/self"), GetClockTicksPerS());
 }
 
 // static
 Value ProcessMetricsHelper::GetCumulativeCPUUsagePerThread() {
-  int ticks_per_s = clock_ticks_per_s.load();
-  if (ticks_per_s == 0) return Value();
+  int ticks_per_s = GetClockTicksPerS();
   ListValue cpu_per_thread;
   FileEnumerator file_enum(FilePath("/proc/self/task"), /*recursive=*/false,
                            FileEnumerator::DIRECTORIES);