Geolocation: move polling policy to its own file.

content/browser/geolocation/wifi_polling_policy.h

+// Copyright (c) 2013 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 CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_
+#define CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_
+
+namespace content {
+
+// Allows sharing and mocking of the update polling policy function.
+class PollingPolicyInterface {

[bulach, 2013/09/06 16:01:38]

nit: jam@ complained that some of the device orientation components had too
generic names, since they weren't in a namespace anymore..

so maybe just "WifiPollingPolicy" would be clearer (and match the file name as
well..)

[Michael van Ouwerkerk, 2013/09/06 19:05:01]

Done.

+ public:
+  virtual ~PollingPolicyInterface() {}
+  // Calculates the new polling interval for wiFi scans, given the previous
+  // interval and whether the last scan produced new results.
+  virtual void UpdatePollingInterval(bool scan_results_differ) = 0;
+  virtual int PollingInterval() = 0;
+  virtual int NoWifiInterval() = 0;

[bulach, 2013/09/06 16:01:38]

nit: I think it needs a private: DISALLOW_COPY_AND_ASSIGN(..);

[Michael van Ouwerkerk, 2013/09/06 19:05:01]

Done.

+};
+
+// Generic polling policy, constants are compile-time parameterized to allow
+// tuning on a per-platform basis.
+template<int DEFAULT_INTERVAL,
+         int NO_CHANGE_INTERVAL,
+         int TWO_NO_CHANGE_INTERVAL,
+         int NO_WIFI_INTERVAL>
+class GenericPollingPolicy : public PollingPolicyInterface {

[bulach, 2013/09/06 16:01:38]

then this can become GenericWifiPollingPolicy?

[Michael van Ouwerkerk, 2013/09/06 19:05:01]

Done.

+ public:
+  GenericPollingPolicy() : polling_interval_(DEFAULT_INTERVAL) {}
+  // PollingPolicyInterface
+  virtual void UpdatePollingInterval(bool scan_results_differ) {
+    if (scan_results_differ) {
+      polling_interval_ = DEFAULT_INTERVAL;
+    } else if (polling_interval_ == DEFAULT_INTERVAL) {
+      polling_interval_ = NO_CHANGE_INTERVAL;
+    } else {
+      DCHECK(polling_interval_ == NO_CHANGE_INTERVAL ||
+             polling_interval_ == TWO_NO_CHANGE_INTERVAL);
+      polling_interval_ = TWO_NO_CHANGE_INTERVAL;
+    }
+  }
+  virtual int PollingInterval() { return polling_interval_; }
+  virtual int NoWifiInterval() { return NO_WIFI_INTERVAL; }
+
+ private:
+  int polling_interval_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_GEOLOCATION_WIFI_POLLING_POLICY_H_