Move supports-high-dpi flag into registry.

ui/gfx/win/dpi.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 "ui/gfx/win/dpi.h"
 
 #include <windows.h>
 #include "base/command_line.h"
 #include "base/win/scoped_hdc.h"
 #include "base/win/windows_version.h"
@@ skipping 80 matching lines @@
 BOOL SetProcessDPIAwareWrapper() {
   typedef BOOL(WINAPI *SetProcessDPIAwarePtr)(VOID);
   SetProcessDPIAwarePtr set_process_dpi_aware_func =
       reinterpret_cast<SetProcessDPIAwarePtr>(
       GetProcAddress(GetModuleHandleA("user32.dll"),
                       "SetProcessDPIAware"));
   return set_process_dpi_aware_func &&
     set_process_dpi_aware_func();
 }
 
+const wchar_t kRegistryProfilePath[] = L"SOFTWARE\\Google\\Chrome\\Profile";
+const wchar_t kHighDPISupport[] = L"high-dpi-support";
+
+DWORD ReadRegistryValue(HKEY root, const wchar_t* base_key,
+    const wchar_t* value_name, DWORD default_value) {
+  base::win::RegKey regKey(HKEY_CURRENT_USER,
+                               base_key,
+                               KEY_QUERY_VALUE);
+  DWORD value;
+  if (regKey.Valid() &&
+      regKey.ReadValueDW(value_name,&value) == ERROR_SUCCESS) {
+    return value;
+  }
+  return default_value;
+}
 }  // namespace
 
 namespace gfx {
 
 float GetModernUIScale() {
   return GetModernUIScaleWrapper();
 }
 
 void InitDeviceScaleFactor(float scale) {
   DCHECK_NE(0.0f, scale);
@@ skipping 19 matching lines @@
 
 float GetDPIScale() {
   if (IsHighDPIEnabled()) {
     return gfx::Display::HasForceDeviceScaleFactor() ?
         gfx::Display::GetForcedDeviceScaleFactor() :
         GetUnforcedDeviceScaleFactor();
   }
   return 1.0;
 }
 
+std::wstring ConvertToWString(const std::string& s) {
+  std::wstring result;
+  result.assign(s.begin(),s.end());
+  return result;
+}
+
 bool IsHighDPIEnabled() {
   // Default is disabled.
-  if (CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kHighDPISupport)) {
-    return CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
-        switches::kHighDPISupport).compare("1") == 0;
-  }
-  return false;
+  static DWORD value = ReadRegistryValue(
+      HKEY_CURRENT_USER,kRegistryProfilePath,
+      ConvertToWString(switches::kHighDPISupport).c_str(),FALSE);
+  return value == 1;
 }
 
 bool IsInHighDPIMode() {
   return GetDPIScale() > 1.0;
 }
 
 void EnableHighDPISupport() {
-  if (IsHighDPIEnabled() &&
-      (base::win::GetVersion() < base::win::VERSION_WIN8_1)) {
+  // TODO: Test to see if this changes in Win8.1 - If not, then change
+  // GetUndocumentedDPIScale...
+  if (IsHighDPIEnabled()) {
     if (!SetProcessDpiAwarenessWrapper(PROCESS_SYSTEM_DPI_AWARE)) {
       SetProcessDPIAwareWrapper();
     }
   }
 }
 
 namespace win {
 
 float GetDeviceScaleFactor() {
   DCHECK_NE(0.0f, g_device_scale_factor);
@@ skipping 61 matching lines @@
 
 double GetUndocumentedDPITouchScale() {
   static double scale =
       (base::win::GetVersion() < base::win::VERSION_WIN8_1) ?
       GetUndocumentedDPIScale() : 1.0;
   return scale;
 }
 
 }  // namespace win
 }  // namespace gfx