[task scheduler] Move files from build_scheduler/ to task_scheduler/

task_scheduler/go/scheduling/task_scheduler.go

-package task_scheduler
+package scheduling
 
 import (
         "fmt"
         "math"
         "path"
         "sort"
         "sync"
         "time"
 
         swarming_api "github.com/luci/luci-go/common/api/swarming/swarming/v1"
         "github.com/skia-dev/glog"
-        "go.skia.org/infra/build_scheduler/go/db"
         "go.skia.org/infra/go/buildbot"
         "go.skia.org/infra/go/gitinfo"
         "go.skia.org/infra/go/gitrepo"
         "go.skia.org/infra/go/isolate"
         "go.skia.org/infra/go/metrics2"
         "go.skia.org/infra/go/swarming"
         "go.skia.org/infra/go/timer"
         "go.skia.org/infra/go/util"
+        "go.skia.org/infra/task_scheduler/go/db"
 )
 
 // TaskScheduler is a struct used for scheduling tasks on bots.
 type TaskScheduler struct {
         cache            db.TaskCache
         db               db.DB
         isolate          *isolate.Client
         period           time.Duration
         queue            []*taskCandidate
         queueMtx         sync.RWMutex
@@ skipping 423 matching lines @@
         s.queueMtx.Lock()
         defer s.queueMtx.Unlock()
         s.queue = rvCandidates
         return nil
 }
 
 // getCandidatesToSchedule matches the list of free Swarming bots to task
 // candidates in the queue and returns the candidates which should be run.
 // Assumes that the tasks are sorted in decreasing order by score.
 func getCandidatesToSchedule(bots []*swarming_api.SwarmingRpcsBotInfo, tasks []*taskCandidate) []*taskCandidate {
-        defer timer.New("task_scheduler.getCandidatesToSchedule").Stop()
+        defer timer.New("scheduling.getCandidatesToSchedule").Stop()
         // Create a bots-by-swarming-dimension mapping.
         botsByDim := map[string]util.StringSet{}
         for _, b := range bots {
                 for _, dim := range b.Dimensions {
                         for _, val := range dim.Value {
                                 d := fmt.Sprintf("%s:%s", dim.Key, val)
                                 if _, ok := botsByDim[d]; !ok {
                                         botsByDim[d] = util.StringSet{}
                                 }
                                 botsByDim[d][b.BotId] = true
@@ skipping 391 matching lines @@
                 }(i, t)
         }
         wg.Wait()
         for _, err := range errs {
                 if err != nil {
                         return err
                 }
         }
         return nil
 }