Fix the black patch which would appear at the top of app windows in Chrome desktop windows with HiD…

chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc

Index: chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
diff --git a/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc b/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
index b2301e69bcfb06ec07e0dd16cf907c8173bb12e1..be9a207739527d43786b82e5496f2942be979e01 100644
--- a/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
+++ b/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
@@ -73,10 +73,19 @@ void AppWindowDesktopWindowTreeHostWin::UpdateDWMFrame() {
   // Otherwise, we need to figure out how to extend the glass in.
   if (app_window_->glass_frame_view()) {
     gfx::Insets insets = app_window_->glass_frame_view()->GetGlassInsets();
-    margins.cxLeftWidth = insets.left();
-    margins.cxRightWidth = insets.right();
-    margins.cyBottomHeight = insets.bottom();
-    margins.cyTopHeight = insets.top();
+    // The DWM API's expect values in pixels. We need to convert from DIP to
+    // pixels here.
+    gfx::Rect insets_rect_in_pixels(insets.left(),
+                                    insets.top(),
+                                    insets.right() - insets.left(),
+                                    insets.bottom() - insets.top());
+    insets_rect_in_pixels = gfx::win::DIPToScreenRect(insets_rect_in_pixels);
+    margins.cxLeftWidth = insets_rect_in_pixels.x();
+    margins.cxRightWidth =
+        insets_rect_in_pixels.x() + insets_rect_in_pixels.width();
+    margins.cyBottomHeight =
+        insets_rect_in_pixels.y() + insets_rect_in_pixels.height();
+    margins.cyTopHeight = insets_rect_in_pixels.y();
   }
 
   DwmExtendFrameIntoClientArea(GetHWND(), &margins);