Enable Per-Monitor Support for Windows 10

chrome/app/chrome_exe_main_win.cc

Index: chrome/app/chrome_exe_main_win.cc
diff --git a/chrome/app/chrome_exe_main_win.cc b/chrome/app/chrome_exe_main_win.cc
index 86677bf87e7255515594a1417cf827e4257dc42f..845dcda706d5049b6733c48baff18ba047d351b5 100644
--- a/chrome/app/chrome_exe_main_win.cc
+++ b/chrome/app/chrome_exe_main_win.cc
@@ -127,7 +127,14 @@ BOOL SetProcessDPIAwareWrapper() {
 }
 
 void EnableHighDPISupport() {
-  if (!SetProcessDpiAwarenessWrapper(PROCESS_SYSTEM_DPI_AWARE)) {
+  // Enable per-monitor DPI for Win10 or above instead of Win8.1 since Win8.1
+  // does not have EnableChildWindowDpiMessage, necessary for correct non-client
+  // area scaling across monitors.
+  PROCESS_DPI_AWARENESS process_dpi_awareness =
+      base::win::GetVersion() >= base::win::VERSION_WIN10
+          ? PROCESS_PER_MONITOR_DPI_AWARE
+          : PROCESS_SYSTEM_DPI_AWARE;
+  if (!SetProcessDpiAwarenessWrapper(process_dpi_awareness)) {
     SetProcessDPIAwareWrapper();
   }
 }