Remove task.h and finish base::Bind() migration.

chrome/browser/chromeos/disks/disk_mount_manager.cc

Index: chrome/browser/chromeos/disks/disk_mount_manager.cc
diff --git a/chrome/browser/chromeos/disks/disk_mount_manager.cc b/chrome/browser/chromeos/disks/disk_mount_manager.cc
index e04abcb13d06d337258cdb16f7ab0bd64c1cd6a6..e831ccf1a1ce2e116e1092784d5107cd031c48dd 100644
--- a/chrome/browser/chromeos/disks/disk_mount_manager.cc
+++ b/chrome/browser/chromeos/disks/disk_mount_manager.cc
@@ -10,6 +10,7 @@
 #include <sys/statvfs.h>
 
 #include "base/bind.h"
+#include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/string_util.h"
 #include "chrome/browser/chromeos/dbus/dbus_thread_manager.h"
@@ -72,7 +73,7 @@ class DiskMountManagerImpl : public DiskMountManager {
         type,
         // When succeeds, OnMountCompleted will be called by
         // "MountCompleted" signal instead.
-        base::Bind(&DoNothing),
+        base::Bind(&base::DoNothing),
         base::Bind(&DiskMountManagerImpl::OnMountCompleted,
                    weak_ptr_factory_.GetWeakPtr(),
                    MOUNT_ERROR_INTERNAL,
@@ -87,7 +88,7 @@ class DiskMountManagerImpl : public DiskMountManager {
     cros_disks_client_->Unmount(mount_path,
                                 base::Bind(&DiskMountManagerImpl::OnUnmountPath,
                                            weak_ptr_factory_.GetWeakPtr()),
-                                base::Bind(&DoNothing));
+                                base::Bind(&base::DoNothing));
   }
 
   // DiskMountManager override.
@@ -219,7 +220,7 @@ class DiskMountManagerImpl : public DiskMountManager {
     cros_disks_client_->EnumerateAutoMountableDevices(
         base::Bind(&DiskMountManagerImpl::OnRequestMountInfo,
                    weak_ptr_factory_.GetWeakPtr()),
-        base::Bind(&DoNothing));
+        base::Bind(&base::DoNothing));
   }
 
   // DiskMountManager override.
@@ -395,7 +396,7 @@ class DiskMountManagerImpl : public DiskMountManager {
             devices[i],
             base::Bind(&DiskMountManagerImpl::OnGetDeviceProperties,
                        weak_ptr_factory_.GetWeakPtr()),
-            base::Bind(&DoNothing));
+            base::Bind(&base::DoNothing));
       }
     }
     // Search and remove disks that are no longer present.
@@ -422,7 +423,7 @@ class DiskMountManagerImpl : public DiskMountManager {
             device_path,
             base::Bind(&DiskMountManagerImpl::OnGetDeviceProperties,
                        weak_ptr_factory_.GetWeakPtr()),
-            base::Bind(&DoNothing));
+            base::Bind(&base::DoNothing));
         return;
       }
       case DISK_REMOVED: {
@@ -526,10 +527,6 @@ class DiskMountManagerImpl : public DiskMountManager {
     return EmptyString();
   }
 
-  // A function to be used as an empty callback.
-  static void DoNothing() {
-  }
-
   // Mount event change observers.
   ObserverList<Observer> observers_;