Enable cpplint for webrtc/modules/pacing and fix all uncovered cpplint errors.

This CL enableds cpplint for webrtc/modules/pacing.

BUG=webrtc:5460
NOTRY=true

TESTED=Fixed issues reported by:
find webrtc/modules/pacing -type f -name *.cc -o -name *.h | xargs cpplint.py
followed by 'git cl presubmit'.

Review URL: https://codereview.webrtc.org/1674423002

Cr-Commit-Position: refs/heads/master@{#11531}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index ce175a4..7388cf8 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -21,6 +21,7 @@
   'webrtc/common_video',
   'webrtc/examples',
   'webrtc/modules/bitrate_controller',
+  'webrtc/modules/pacing',
   'webrtc/modules/remote_bitrate_estimator',
   'webrtc/modules/rtp_rtcp',
   'webrtc/modules/video_coding',
diff --git a/webrtc/modules/pacing/mock/mock_paced_sender.h b/webrtc/modules/pacing/mock/mock_paced_sender.h
index 01d5f6a..c710dbc 100644
--- a/webrtc/modules/pacing/mock/mock_paced_sender.h
+++ b/webrtc/modules/pacing/mock/mock_paced_sender.h
@@ -11,10 +11,10 @@
 #ifndef WEBRTC_MODULES_PACING_MOCK_MOCK_PACED_SENDER_H_
 #define WEBRTC_MODULES_PACING_MOCK_MOCK_PACED_SENDER_H_
 
-#include "testing/gmock/include/gmock/gmock.h"
-
 #include <vector>
 
+#include "testing/gmock/include/gmock/gmock.h"
+
 #include "webrtc/modules/pacing/paced_sender.h"
 #include "webrtc/system_wrappers/include/clock.h"
 
diff --git a/webrtc/modules/pacing/paced_sender.cc b/webrtc/modules/pacing/paced_sender.cc
index 25ca2cf..23b172c 100644
--- a/webrtc/modules/pacing/paced_sender.cc
+++ b/webrtc/modules/pacing/paced_sender.cc
@@ -10,9 +10,11 @@
 
 #include "webrtc/modules/pacing/paced_sender.h"
 
+#include <algorithm>
 #include <map>
 #include <queue>
 #include <set>
+#include <vector>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
diff --git a/webrtc/modules/pacing/paced_sender_unittest.cc b/webrtc/modules/pacing/paced_sender_unittest.cc
index 588bf3b..f40dba3 100644
--- a/webrtc/modules/pacing/paced_sender_unittest.cc
+++ b/webrtc/modules/pacing/paced_sender_unittest.cc
@@ -288,7 +288,7 @@
                   TimeToSendPacket(ssrc, queued_sequence_number++, _, false))
           .Times(1)
           .WillRepeatedly(Return(true));
-   }
+    }
     EXPECT_EQ(0, send_bucket_->TimeUntilNextProcess());
     EXPECT_EQ(0, send_bucket_->Process());
   }
@@ -422,7 +422,8 @@
   int64_t start_time = clock_.TimeInMilliseconds();
   size_t media_bytes = 0;
   while (clock_.TimeInMilliseconds() - start_time < kBitrateWindow) {
-    size_t media_payload = rand() % 100 + 200;  // [200, 300] bytes.
+    int rand_value = rand();  // NOLINT (rand_r instead of rand)
+    size_t media_payload = rand_value % 100 + 200;  // [200, 300] bytes.
     send_bucket_->InsertPacket(PacedSender::kNormalPriority, ssrc,
                                sequence_number++, capture_time_ms,
                                media_payload, false);
diff --git a/webrtc/modules/pacing/packet_router.cc b/webrtc/modules/pacing/packet_router.cc
index e98ab0c..ac75d2c 100644
--- a/webrtc/modules/pacing/packet_router.cc
+++ b/webrtc/modules/pacing/packet_router.cc
@@ -40,7 +40,7 @@
   }
   return false;
 }
-}
+}  // namespace
 
 PacketRouter::PacketRouter() : transport_seq_(0) {
   pacer_thread_checker_.DetachFromThread();