Fixed issues flagged by cpplint.

Review: https://reviews.apache.org/r/71996
diff --git a/src/master/authorization.cpp b/src/master/authorization.cpp
index ea10175..77719eb 100644
--- a/src/master/authorization.cpp
+++ b/src/master/authorization.cpp
@@ -331,9 +331,9 @@
       case Resource::DiskInfo::Source::PATH:
       case Resource::DiskInfo::Source::RAW:
         return None();
-   }
+    }
 
-   return None();
+    return None();
   })();
 
   if (action.isNone()) {
@@ -362,9 +362,9 @@
       case Resource::DiskInfo::Source::UNKNOWN:
       case Resource::DiskInfo::Source::PATH:
         return None();
-   }
+    }
 
-   return None();
+    return None();
   })();
 
   if (action.isNone()) {
diff --git a/src/master/authorization.hpp b/src/master/authorization.hpp
index f28b29f..562449b 100644
--- a/src/master/authorization.hpp
+++ b/src/master/authorization.hpp
@@ -22,8 +22,11 @@
 #include <vector>
 
 #include <stout/option.hpp>
+#include <stout/try.hpp>
 
-#include <mesos/mesos.pb.h>
+#include <mesos/mesos.hpp>
+#include <mesos/resources.hpp>
+
 #include <mesos/authorizer/authorizer.pb.h>
 
 namespace mesos {
@@ -79,14 +82,14 @@
 
   // Returns Error if disk type is not supported.
   //
-  // TODO (asekretenko): Change return type to ActionObject after
+  // TODO(asekretenko): Change return type to ActionObject after
   // authorization of invalid operations no longer occurs (see MESOS-10083).
   static Try<ActionObject> createDisk(
       const Offer::Operation::CreateDisk& createDisk);
 
   // Returns Error if disk type is not supported.
   //
-  // TODO (asekretenko): Change return type to ActionObject after
+  // TODO(asekretenko): Change return type to ActionObject after
   // authorization of invalid operations no longer occurs (see MESOS-10083).
   static Try<ActionObject> destroyDisk(
       const Offer::Operation::DestroyDisk& destroyDisk);
diff --git a/src/master/master.cpp b/src/master/master.cpp
index 23f747c..d802b3e 100644
--- a/src/master/master.cpp
+++ b/src/master/master.cpp
@@ -3697,7 +3697,6 @@
     const Option<Principal>& principal,
     ActionObject&& actionObject)
 {
-
   if (authorizer.isNone()) {
     return true;
   }
@@ -3746,7 +3745,7 @@
 
   vector<Future<bool>> authorizations;
   authorizations.reserve(actionObjects.size());
-  for (ActionObject& actionObject: actionObjects) {
+  for (ActionObject& actionObject : actionObjects) {
     authorizations.push_back(authorize(principal, std::move(actionObject)));
   }
 
@@ -4321,7 +4320,7 @@
     ? Principal(framework->info.principal())
     : Option<Principal>::none();
 
-  // TODO (asekretenko): use background-refreshed ObjectApprovers
+  // TODO(asekretenko): Use background-refreshed ObjectApprovers
   // instead of asynchronous authorization.
   vector<Future<bool>> futures;
   for (const Offer::Operation& operation : accept.operations()) {
diff --git a/src/tests/containerizer/io_switchboard_tests.cpp b/src/tests/containerizer/io_switchboard_tests.cpp
index 1b347eb..20d4ea7 100644
--- a/src/tests/containerizer/io_switchboard_tests.cpp
+++ b/src/tests/containerizer/io_switchboard_tests.cpp
@@ -167,7 +167,8 @@
 
           if (processIO->data().type() == agent::ProcessIO::Data::STDOUT) {
             stdoutReceived += processIO->data().data();
-          } else if (processIO->data().type() == agent::ProcessIO::Data::STDERR) {
+          } else if (
+              processIO->data().type() == agent::ProcessIO::Data::STDERR) {
             stderrReceived += processIO->data().data();
           }
         }