Cleanup std::chrono usage

Use mbgl::Duration and mbgl::{,Milli}Seconds whenever possible.

src/mbgl/map/map_data.hpp

@@ -26,7 +26,7 @@ public:
         , pixelRatio(pixelRatio_)
         , annotationManager(pixelRatio)
         , animationTime(Duration::zero())
-        , defaultFadeDuration(mode_ == MapMode::Continuous ? std::chrono::milliseconds(300) : Duration::zero())
+        , defaultFadeDuration(mode_ == MapMode::Continuous ? Milliseconds(300) : Duration::zero())
         , defaultTransitionDuration(Duration::zero())
         , defaultTransitionDelay(Duration::zero()) {
         assert(pixelRatio > 0);

src/mbgl/map/transform.cpp

@@ -9,6 +9,7 @@
 #include <mbgl/util/tile_coordinate.hpp>
 #include <mbgl/platform/log.hpp>
 #include <mbgl/platform/platform.hpp>
+#include <mbgl/util/chrono.hpp>
 
 #include <cstdio>
 #include <cmath>
@@ -281,8 +282,7 @@ void Transform::flyTo(const CameraOptions &camera, const AnimationOptions &anima
         if (animation.velocity) {
             velocity = *animation.velocity / rho;
         }
-        duration = std::chrono::duration_cast<std::chrono::steady_clock::duration>(
-            std::chrono::duration<double, std::chrono::seconds::period>(S / velocity));
+        duration = std::chrono::duration_cast<Duration>(std::chrono::duration<double>(S / velocity));
     }
     if (duration == Duration::zero()) {
         // Perform an instantaneous transition.

src/mbgl/style/function.cpp

@@ -1,6 +1,7 @@
 #include <mbgl/style/function.hpp>
 #include <mbgl/style/style_calculation_parameters.hpp>
 #include <mbgl/util/interpolate.hpp>
+#include <mbgl/util/chrono.hpp>
 
 #include <cmath>
 

src/mbgl/style/property_parsing.cpp

@@ -214,11 +214,11 @@ optional<PropertyTransition> parseProperty(const char *, const JSValue& value) {
     if (value.IsObject()) {
         bool parsed = false;
         if (value.HasMember("duration") && value["duration"].IsNumber()) {
-            transition.duration = Duration(std::chrono::milliseconds(value["duration"].GetUint()));
+            transition.duration.emplace(Milliseconds(value["duration"].GetUint()));
             parsed = true;
         }
         if (value.HasMember("delay") && value["delay"].IsNumber()) {
-            transition.delay = Duration(std::chrono::milliseconds(value["delay"].GetUint()));
+            transition.delay.emplace(Milliseconds(value["delay"].GetUint()));
             parsed = true;
         }
         if (!parsed) {

src/mbgl/util/stopwatch.cpp

@@ -1,6 +1,7 @@
 #ifndef DISABLE_STOPWATCH
 #include <mbgl/util/stopwatch.hpp>
 #include <mbgl/util/string.hpp>
+#include <mbgl/util/chrono.hpp>
 #include <mbgl/platform/log.hpp>
 
 #include <iostream>