Remove dead code from performance monitor

This CL should not change any behavior. It's removing some old code
no longer used.

R=oysteine@chromium.org

Change-Id: Icfdbdcc5a5e40d740401ecb9b25536425c4c5e61
Reviewed-on: https://chromium-review.googlesource.com/1178383Reviewed-by: oysteine <oysteine@chromium.org>
Commit-Queue: Etienne Bergeron <etienneb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585212}

chrome/browser/performance_monitor/performance_monitor.cc

@@ -71,9 +71,9 @@ void GatherMetricsForRenderProcess(content::RenderProcessHost* host,
 
 }  // namespace
 
-PerformanceMonitor::PerformanceMonitor() {}
+PerformanceMonitor::PerformanceMonitor() = default;
 
-PerformanceMonitor::~PerformanceMonitor() {}
+PerformanceMonitor::~PerformanceMonitor() = default;
 
 // static
 PerformanceMonitor* PerformanceMonitor::GetInstance() {

chrome/browser/performance_monitor/process_metrics_history.cc

@@ -17,26 +17,13 @@
 
 namespace performance_monitor {
 
-namespace {
-
-const char kBrowserProcessTrigger[] =
-    "ProcessMetricsHistory.BrowserProcess.HighCPU";
-const char kGPUProcessTrigger[] = "ProcessMetricsHistory.GPUProcess.HighCPU";
-const char kExtensionPersistentProcessTrigger[] =
-    "ProcessMetricsHistory.ExtensionPersistentProcess.HighCPU";
-
-}  // namespace
-
 // If a process is consistently above this CPU utilization percentage over time,
 // we consider it as high and may take action.
 const float kHighCPUUtilizationThreshold = 90.0f;
 
-ProcessMetricsHistory::ProcessMetricsHistory()
-    : last_update_sequence_(0), cpu_usage_(0.0), trace_trigger_handle_(-1) {
-}
+ProcessMetricsHistory::ProcessMetricsHistory() = default;
 
-ProcessMetricsHistory::~ProcessMetricsHistory() {
-}
+ProcessMetricsHistory::~ProcessMetricsHistory() = default;
 
 void ProcessMetricsHistory::Initialize(
     const ProcessMetricsMetadata& process_data,
@@ -53,28 +40,6 @@ void ProcessMetricsHistory::Initialize(
   process_metrics_ =
       base::ProcessMetrics::CreateProcessMetrics(process_data_.handle);
 #endif
-
-  const char* trigger_name = NULL;
-  switch (process_data_.process_type) {
-    case content::PROCESS_TYPE_BROWSER:
-      trigger_name = kBrowserProcessTrigger;
-      break;
-    case content::PROCESS_TYPE_GPU:
-      trigger_name = kGPUProcessTrigger;
-      break;
-  }
-  switch (process_data_.process_subtype) {
-    case kProcessSubtypeExtensionPersistent:
-      trigger_name = kExtensionPersistentProcessTrigger;
-      break;
-    default:
-      break;
-  }
-  if (trigger_name) {
-    trace_trigger_handle_ =
-        content::BackgroundTracingManager::GetInstance()->RegisterTriggerType(
-            trigger_name);
-  }
 }
 
 void ProcessMetricsHistory::SampleMetrics() {
@@ -196,13 +161,6 @@ void ProcessMetricsHistory::RunPerformanceTriggers() {
       }
       break;
   }
-
-  if (cpu_usage_ > kHighCPUUtilizationThreshold &&
-      trace_trigger_handle_ != -1) {
-    content::BackgroundTracingManager::GetInstance()->TriggerNamedEvent(
-        trace_trigger_handle_,
-        content::BackgroundTracingManager::StartedFinalizingCallback());
-  }
 }
 
 }  // namespace performance_monitor

chrome/browser/performance_monitor/process_metrics_history.h

@@ -10,7 +10,6 @@
 #include "base/macros.h"
 #include "base/process/process_handle.h"
 #include "build/build_config.h"
-#include "content/public/browser/background_tracing_manager.h"
 #include "content/public/browser/child_process_data.h"
 #include "content/public/common/process_type.h"
 
@@ -66,19 +65,17 @@ class ProcessMetricsHistory {
   // renderer processes.
   ProcessMetricsMetadata process_data_;
   std::unique_ptr<base::ProcessMetrics> process_metrics_;
-  int last_update_sequence_;
+  int last_update_sequence_ = 0;
 
-  double cpu_usage_;
+  double cpu_usage_ = 0.0;
 
 #if defined(OS_MACOSX) || defined(OS_LINUX) || defined(OS_AIX)
-  int idle_wakeups_;
+  int idle_wakeups_ = 0;
 #endif
 #if defined(OS_MACOSX)
-  int package_idle_wakeups_;
+  int package_idle_wakeups_ = 0;
 #endif
 
-  content::BackgroundTracingManager::TriggerHandle trace_trigger_handle_;
-
   DISALLOW_ASSIGN(ProcessMetricsHistory);
 };