[Night Light] CL12: String changes and fix frequent requests.

chrome/browser/chromeos/night_light/night_light_client.cc

 // 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.
 
 #include "chrome/browser/chromeos/night_light/night_light_client.h"
 
+#include <algorithm>
+
 #include "ash/public/interfaces/constants.mojom.h"
+#include "base/time/clock.h"
+#include "base/time/tick_clock.h"
 #include "content/public/common/service_manager_connection.h"
 #include "services/service_manager/public/cpp/connector.h"
 
 namespace {
 
 // Delay to wait for a response to our geolocation request, if we get a response
 // after which, we will consider the request a failure.
 constexpr base::TimeDelta kGeolocationRequestTimeout =
     base::TimeDelta::FromSeconds(60);
 
 // Minimum delay to wait to fire a new request after a previous one failing.
 constexpr base::TimeDelta kMinimumDelayAfterFailure =
     base::TimeDelta::FromSeconds(60);
 
 // Delay to wait to fire a new request after a previous one succeeding.
 constexpr base::TimeDelta kNextRequestDelayAfterSuccess =
     base::TimeDelta::FromDays(1);
 
 }  // namespace
 
 NightLightClient::NightLightClient(
-    net::URLRequestContextGetter* url_context_getter)
+    net::URLRequestContextGetter* url_context_getter,
+    base::TickClock* tick_clock,
+    base::Clock* clock)
     : provider_(
           url_context_getter,
           chromeos::SimpleGeolocationProvider::DefaultGeolocationProviderURL()),
       binding_(this),
-      backoff_delay_(kMinimumDelayAfterFailure) {}
+      backoff_delay_(kMinimumDelayAfterFailure),
+      timer_(tick_clock),
+      clock_(clock) {}
+
+NightLightClient::NightLightClient(
+    net::URLRequestContextGetter* url_context_getter)
+    : NightLightClient(url_context_getter, nullptr, nullptr) {}
 
 NightLightClient::~NightLightClient() {}
 
 void NightLightClient::Start() {
   if (!night_light_controller_) {
     service_manager::Connector* connector =
         content::ServiceManagerConnection::GetForProcess()->GetConnector();
     connector->BindInterface(ash::mojom::kServiceName,
                              &night_light_controller_);
   }
   ash::mojom::NightLightClientPtr client;
   binding_.Bind(mojo::MakeRequest(&client));
   night_light_controller_->SetClient(std::move(client));
 }
 
 void NightLightClient::OnScheduleTypeChanged(
     ash::mojom::NightLightController::ScheduleType new_type) {
   if (new_type ==
       ash::mojom::NightLightController::ScheduleType::kSunsetToSunrise) {
-    // Schedule an immediate request.
     using_geoposition_ = true;
-    ScheduleNextRequest(base::TimeDelta::FromSeconds(0));
+    // No need to request a new position if we already have a valid one from a
+    // request less than kNextRequestDelayAfterSuccess ago.
+    base::Time now = GetNow();
+    if ((now - last_successful_geo_request_time_) <
+        kNextRequestDelayAfterSuccess) {
+      // Use the current valid position to update NightLightController.
+      SendCurrentGeoposition();
+    }
+
+    // Next request is either immediate or kNextRequestDelayAfterSuccess later
+    // than the last success time, whichever is greater.
+    ScheduleNextRequest(std::max(base::TimeDelta::FromSeconds(0),
+                                 last_successful_geo_request_time_ +
+                                     kNextRequestDelayAfterSuccess - now));

[stevenjb, 2017/07/01 00:02:35]

nit: With the extra complexity here, invert the if and early exit for the
simpler case to reduce indentation of this more complicated case.

[afakhry, 2017/07/01 00:26:14]

Done.

   } else {
     using_geoposition_ = false;
     timer_.Stop();
   }
 }
 
+// static
+base::TimeDelta NightLightClient::GetNextRequestDelayAfterSuccessForTesting() {
+  return kNextRequestDelayAfterSuccess;
+}
+
 void NightLightClient::SetNightLightControllerPtrForTesting(
     ash::mojom::NightLightControllerPtr controller) {
   night_light_controller_ = std::move(controller);
 }
 
 void NightLightClient::FlushNightLightControllerForTesting() {
   night_light_controller_.FlushForTesting();
 }
 
 void NightLightClient::OnGeoposition(const chromeos::Geoposition& position,
@@ skipping 10 matching lines @@
       elapsed > kGeolocationRequestTimeout) {
     // Don't send invalid positions to ash.
     // On failure, we schedule another request after the current backoff delay.
     ScheduleNextRequest(backoff_delay_);
 
     // If another failure occurs next, our backoff delay should double.
     backoff_delay_ *= 2;
     return;
   }
 
-  night_light_controller_->SetCurrentGeoposition(
-      ash::mojom::SimpleGeoposition::New(position.latitude,
-                                         position.longitude));
+  last_successful_geo_request_time_ = GetNow();
+
+  latitude_ = position.latitude;
+  longitude_ = position.longitude;
+  SendCurrentGeoposition();
 
   // On success, reset the backoff delay to its minimum value, and schedule
   // another request.
   backoff_delay_ = kMinimumDelayAfterFailure;
   ScheduleNextRequest(kNextRequestDelayAfterSuccess);
 }
 
+base::Time NightLightClient::GetNow() const {
+  return clock_ ? clock_->Now() : base::Time::Now();
+}
+
+void NightLightClient::SendCurrentGeoposition() {
+  night_light_controller_->SetCurrentGeoposition(
+      ash::mojom::SimpleGeoposition::New(latitude_, longitude_));
+}
+
 void NightLightClient::ScheduleNextRequest(base::TimeDelta delay) {
   timer_.Start(FROM_HERE, delay, this, &NightLightClient::RequestGeoposition);
 }
 
 void NightLightClient::RequestGeoposition() {
   provider_.RequestGeolocation(
       kGeolocationRequestTimeout, false /* send_wifi_access_points */,
       false /* send_cell_towers */,
       base::Bind(&NightLightClient::OnGeoposition, base::Unretained(this)));
 }