[GRC] Decouple Render Process CPU Measurement from CU Graph

chrome/browser/resource_coordinator/resource_coordinator_render_process_probe.h

Index: chrome/browser/resource_coordinator/resource_coordinator_render_process_probe.h
diff --git a/chrome/browser/resource_coordinator/resource_coordinator_render_process_probe.h b/chrome/browser/resource_coordinator/resource_coordinator_render_process_probe.h
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index 0000000000000000000000000000000000000000..7ac3e57f62945f5152e8bef443edd77eec1869af
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+++ b/chrome/browser/resource_coordinator/resource_coordinator_render_process_probe.h
@@ -0,0 +1,66 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_RESOURCE_COORDINATOR_RESOURCE_COORDINATOR_RENDER_PROCESS_PROBE_H_
+#define CHROME_BROWSER_RESOURCE_COORDINATOR_RESOURCE_COORDINATOR_RENDER_PROCESS_PROBE_H_
+
+#include <memory>
+#include <unordered_map>
+
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/process/process_handle.h"
+#include "base/process/process_metrics.h"
+#include "base/timer/timer.h"
+
+namespace resource_coordinator {
+
+// |ResourceCoordinatorRenderProcessProbe| collects measurements about render
+// processes and propagates them to the |resource_coordinator| service.
+class ResourceCoordinatorRenderProcessProbe {
+ public:
+  // Returns the current |ResourceCoordinatorRenderProcessProbe| instance
+  // if one exists; otherwise it constructs a new instance.
+  static ResourceCoordinatorRenderProcessProbe* GetInstance();
+
+  // Start collecting render process metrics.
+  void StartGatherCycle();
+
+  // Collects measurements for all active render processes and then
+  // propagates them to their corresponding |ResourceCoordinatorInterface|.
+  void CollectAndSendMeasurements();
+
+ private:
+  friend struct base::LazyInstanceTraitsBase<
+      ResourceCoordinatorRenderProcessProbe>;
+
+  struct ProcessMetricsState {
+    ProcessMetricsState();
+    ~ProcessMetricsState();
+    size_t last_tick_active;
+    std::unique_ptr<base::ProcessMetrics> metrics;
+  };
+
+  using ProcessMetricsStateMap =
+      std::unordered_map<base::ProcessHandle, ProcessMetricsState>;
+
+  ResourceCoordinatorRenderProcessProbe();
+  ~ResourceCoordinatorRenderProcessProbe();
+
+  // A map of currently running ProcessHandles to Process.
+  ProcessMetricsStateMap process_metrics_states_;
+
+  // Timer to signal the |ResourceCoordinatorRenderProcessProbe| instance
+  // to conduct its measurements as a regular interval;
+  base::OneShotTimer repeating_timer_;
+
+  // Number of measurements collected so far.
+  size_t ticks_ = 0u;
+
+  DISALLOW_COPY_AND_ASSIGN(ResourceCoordinatorRenderProcessProbe);
+};
+
+}  // namespace resource_coordinator
+
+#endif  // CHROME_BROWSER_RESOURCE_COORDINATOR_RESOURCE_COORDINATOR_RENDER_PROCESS_PROBE_H_