GetDeviceCaps doesn't need to be scaled.

chrome/browser/metrics/metrics_log.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/metrics/metrics_log.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 40 matching lines @@
 #include "gpu/config/gpu_info.h"
 #include "ui/gfx/screen.h"
 #include "url/gurl.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/build_info.h"
 #endif
 
 #if defined(OS_WIN)
 #include "base/win/metro.h"
-#include "ui/gfx/win/dpi.h"
 
 // http://blogs.msdn.com/oldnewthing/archive/2004/10/25/247180.aspx
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 #endif
 
 using content::GpuDataManager;
 using metrics::OmniboxEventProto;
 using metrics::PerfDataProto;
 using metrics::ProfilerEventProto;
 using metrics::SystemProfileProto;
@@ skipping 226 matching lines @@
   const double kMillimetersPerInch = 25.4;
   ScreenDPIInformation* screen_info =
       reinterpret_cast<ScreenDPIInformation*>(dwData);
   // Size of screen, in mm.
   DWORD size_x = GetDeviceCaps(hdc, HORZSIZE);
   DWORD size_y = GetDeviceCaps(hdc, VERTSIZE);
   double dpi_x = (size_x > 0) ?
       GetDeviceCaps(hdc, HORZRES) / (size_x / kMillimetersPerInch) : 0;
   double dpi_y = (size_y > 0) ?
       GetDeviceCaps(hdc, VERTRES) / (size_y / kMillimetersPerInch) : 0;
-  dpi_x *= gfx::win::GetUndocumentedDPIScale();
-  dpi_y *= gfx::win::GetUndocumentedDPIScale();
   screen_info->max_dpi_x = std::max(dpi_x, screen_info->max_dpi_x);
   screen_info->max_dpi_y = std::max(dpi_y, screen_info->max_dpi_y);
   return TRUE;
 }
 
 void WriteScreenDPIInformationProto(SystemProfileProto::Hardware* hardware) {
   HDC desktop_dc = GetDC(NULL);
   if (desktop_dc) {
     ScreenDPIInformation si = {0, 0};
     if (EnumDisplayMonitors(desktop_dc, NULL, GetMonitorDPICallback,
@@ skipping 631 matching lines @@
 
       paired_device->set_vendor_prefix(vendor_prefix);
     }
 
     paired_device->set_vendor_id(device->GetVendorID());
     paired_device->set_product_id(device->GetProductID());
     paired_device->set_device_id(device->GetDeviceID());
   }
 #endif  // defined(OS_CHROMEOS)
 }