Remove more unmapped media galleries histograms.

components/storage_monitor/storage_monitor_linux.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // StorageMonitorLinux implementation.
 
 #include "components/storage_monitor/storage_monitor_linux.h"
 
 #include <mntent.h>
 #include <stdint.h>
@@ skipping 37 matching lines @@
 const char kModelID[] = "ID_MODEL_ID";
 const char kRemovableSysAttr[] = "removable";
 const char kSerialShort[] = "ID_SERIAL_SHORT";
 const char kSizeSysAttr[] = "size";
 const char kVendor[] = "ID_VENDOR";
 const char kVendorID[] = "ID_VENDOR_ID";
 
 // Construct a device id using label or manufacturer (vendor and model) details.
 std::string MakeDeviceUniqueId(struct udev_device* device) {
   std::string uuid = device::UdevDeviceGetPropertyValue(device, kFsUUID);
-  // Keep track of device uuid, to see how often we receive empty uuid values.
-  UMA_HISTOGRAM_BOOLEAN(
-      "RemovableDeviceNotificationsLinux.device_file_system_uuid_available",
-      !uuid.empty());
-
   if (!uuid.empty())
     return kFSUniqueIdPrefix + uuid;
 
   // If one of the vendor, model, serial information is missing, its value
   // in the string is empty.
   // Format: VendorModelSerial:VendorInfo:ModelInfo:SerialShortInfo
   // E.g.: VendorModelSerial:Kn:DataTravel_12.10:8000000000006CB02CDB
   std::string vendor = device::UdevDeviceGetPropertyValue(device, kVendorID);
   std::string model = device::UdevDeviceGetPropertyValue(device, kModelID);
   std::string serial_short =
@@ skipping 386 matching lines @@
   mount_priority_map_[mount_device][mount_point] = removable;
   receiver()->ProcessAttach(*storage_info);
 }
 
 StorageMonitor* StorageMonitor::CreateInternal() {
   const base::FilePath kDefaultMtabPath("/etc/mtab");
   return new StorageMonitorLinux(kDefaultMtabPath);
 }
 
 }  // namespace storage_monitor