Create a thermal manager class and wire it in to nanobench behind a flag

tools/ThermalManager.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef ThermalManager_DEFINED
+#define ThermalManager_DEFINED
+
+#include "SkString.h"
+#include "SkTArray.h"
+
+#if defined(SK_BUILD_FOR_ANDROID) || defined(SK_BUILD_FOR_UNIX)
+#    define THERMAL_MANAGER_SUPPORTED
+#endif
+
+#ifdef THERMAL_MANAGER_SUPPORTED
+
+/*
+ * This simple class monitors the thermal part of sysfs to ensure we don't trigger thermal events
+ */
+
+class ThermalManager {
+public:
+    ThermalManager(int32_t threshold, uint32_t sleepIntervalMs, uint32_t timeoutMs);
+
+    bool coolOffIfNecessary();
+
+private:
+    static int32_t OpenFileAndReadInt32(const char* path);
+
+    // current temperature can be read from /thermalZonePath/temp
+    static int32_t GetTemp(SkString thermalZonePath) {
+        SkString temperatureFilePath(thermalZonePath);
+        temperatureFilePath.appendf("/temp");
+        return OpenFileAndReadInt32(temperatureFilePath.c_str());
+    }
+
+    struct TripPoint {
+        TripPoint(SkString thermalZoneRoot, SkString pointName, int32_t threshold);
+
+        bool willTrip();
+
+        SkString fThermalZoneRoot;
+        SkString fPointName;
+        int32_t fBase;
+        int32_t fPoint;
+        int32_t fThreshold;
+
+        // Certain trip points seem to start tripped.  For example, I have seen trip points of 0 or
+        // negative numbers.
+        bool fDisabled;
+    };
+
+    SkTArray<TripPoint> fTripPoints;
+    uint32_t fSleepIntervalMs;
+    uint32_t fTimeoutMs;
+};
+#endif
+#endif