Fix Lint and ClangTidy warnings. (#485)

cartographer/io/draw_trajectories.cc

@@ -23,7 +23,8 @@ namespace cartographer {
 namespace io {
 
 void DrawTrajectory(const mapping::proto::Trajectory& trajectory,
-                    const FloatColor& color, PoseToPixelFunction pose_to_pixel,
+                    const FloatColor& color,
+                    const PoseToPixelFunction& pose_to_pixel,
                     cairo_surface_t* surface) {
   if (trajectory.node_size() == 0) {
     return;

cartographer/io/draw_trajectories.h

@@ -32,7 +32,8 @@ using PoseToPixelFunction =
 // 'pose_to_pixel' function must translate a trajectory node's position into the
 // pixel on 'surface'.
 void DrawTrajectory(const mapping::proto::Trajectory& trajectory,
-                    const FloatColor& color, PoseToPixelFunction pose_to_pixel,
+                    const FloatColor& color,
+                    const PoseToPixelFunction& pose_to_pixel,
                     cairo_surface_t* surface);
 
 }  // namespace io

cartographer/mapping/pose_extrapolator.cc

@@ -26,9 +26,9 @@ namespace cartographer {
 namespace mapping {
 
 PoseExtrapolator::PoseExtrapolator(const common::Duration pose_queue_duration,
-                                   double gravity_time_constant)
+                                   double imu_gravity_time_constant)
     : pose_queue_duration_(pose_queue_duration),
-      gravity_time_constant_(gravity_time_constant) {}
+      gravity_time_constant_(imu_gravity_time_constant) {}
 
 std::unique_ptr<PoseExtrapolator> PoseExtrapolator::InitializeWithImu(
     const common::Duration pose_queue_duration,

cartographer/mapping_3d/local_trajectory_builder.cc

@@ -131,7 +131,7 @@ LocalTrajectoryBuilder::AddAccumulatedRangeData(
   const sensor::PointCloud filtered_point_cloud_in_tracking =
       adaptive_voxel_filter.Filter(filtered_range_data.returns);
   if (options_.use_online_correlative_scan_matching()) {
-    // We take a copy since we use 'intial_ceres_pose' as an output argument.
+    // We take a copy since we use 'initial_ceres_pose' as an output argument.
     const transform::Rigid3d initial_pose = initial_ceres_pose;
     real_time_correlative_scan_matcher_->Match(
         initial_pose, filtered_point_cloud_in_tracking,

cartographer/mapping_3d/scan_matching/fast_correlative_scan_matcher_test.cc

@@ -37,7 +37,7 @@ class FastCorrelativeScanMatcherTest : public ::testing::Test {
  protected:
   FastCorrelativeScanMatcherTest()
       : range_data_inserter_(CreateRangeDataInserterTestOptions()),
-        options_(CreateFastCorrelativeScanMatcherTestOptions(5)){};
+        options_(CreateFastCorrelativeScanMatcherTestOptions(5)) {}
 
   void SetUp() override {
     point_cloud_ = {