Fix for 593676 - Minimizes/eliminates momentary flash of Windows frame

ui/views/win/hwnd_message_handler.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/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <oleacc.h>
 #include <shellapi.h>
 #include <tchar.h>
@@ skipping 504 matching lines @@
       *show_state = ui::SHOW_STATE_NORMAL;
   }
 }
 
 void HWNDMessageHandler::SetBounds(const gfx::Rect& bounds_in_pixels,
                                    bool force_size_changed) {
   background_fullscreen_hack_ = false;
   SetBoundsInternal(bounds_in_pixels, force_size_changed);
 }
 
+void HWNDMessageHandler::SetDwmFrameExtension(DwmFrameState state) {
+  if (!delegate_->HasFrame() && ui::win::IsAeroGlassEnabled() &&
+      (window_ex_style() & WS_EX_COMPOSITED) == 0) {
+    MARGINS m = {0, 0, 0, 0};
+    if (state == DwmFrameState::ON)
+      m = {0, 0, 1, 0};
+    DwmExtendFrameIntoClientArea(hwnd(), &m);
+  }
+}
+
 void HWNDMessageHandler::SetSize(const gfx::Size& size) {
   SetWindowPos(hwnd(), NULL, 0, 0, size.width(), size.height(),
                SWP_NOACTIVATE | SWP_NOZORDER | SWP_NOMOVE);
 }
 
 void HWNDMessageHandler::CenterWindow(const gfx::Size& size) {
   HWND parent = GetParent(hwnd());
   if (!IsWindow(hwnd()))
     parent = ::GetWindow(hwnd(), GW_OWNER);
   gfx::CenterAndSizeWindow(parent, hwnd(), size);
@@ skipping 1806 matching lines @@
   }
 
   if (ScopedFullscreenVisibility::IsHiddenForFullscreen(hwnd())) {
     // Prevent the window from being made visible if we've been asked to do so.
     // See comment in header as to why we might want this.
     window_pos->flags &= ~SWP_SHOWWINDOW;
   }
 
   if (window_pos->flags & SWP_SHOWWINDOW)
     delegate_->HandleVisibilityChanging(true);
-  else if (window_pos->flags & SWP_HIDEWINDOW)
+  else if (window_pos->flags & SWP_HIDEWINDOW) {
+    SetDwmFrameExtension(DwmFrameState::OFF);
     delegate_->HandleVisibilityChanging(false);
+  }
 
   SetMsgHandled(FALSE);
 }
 
 void HWNDMessageHandler::OnWindowPosChanged(WINDOWPOS* window_pos) {
   if (DidClientAreaSizeChange(window_pos))
     ClientAreaSizeChanged();
-  if (!delegate_->HasFrame() && window_pos->flags & SWP_FRAMECHANGED &&
-      ui::win::IsAeroGlassEnabled() &&
-      (window_ex_style() & WS_EX_COMPOSITED) == 0) {
-    MARGINS m = {10, 10, 10, 10};
-    DwmExtendFrameIntoClientArea(hwnd(), &m);
-  }
+  if (window_pos->flags & SWP_FRAMECHANGED)
+    SetDwmFrameExtension(DwmFrameState::ON);
   if (window_pos->flags & SWP_SHOWWINDOW) {
     delegate_->HandleVisibilityChanged(true);
     if (direct_manipulation_helper_)
       direct_manipulation_helper_->Activate(hwnd());
+    SetDwmFrameExtension(DwmFrameState::ON);
   } else if (window_pos->flags & SWP_HIDEWINDOW) {
     delegate_->HandleVisibilityChanged(false);
     if (direct_manipulation_helper_)
       direct_manipulation_helper_->Deactivate(hwnd());
   }
   if (sent_window_size_changing_) {
     sent_window_size_changing_ = false;
     delegate_->HandleWindowSizeChanged();
   }
   SetMsgHandled(FALSE);
@@ skipping 356 matching lines @@
   MONITORINFO monitor_info = {sizeof(monitor_info)};
   GetMonitorInfo(MonitorFromWindow(hwnd(), MONITOR_DEFAULTTOPRIMARY),
                  &monitor_info);
   gfx::Rect shrunk_rect(monitor_info.rcMonitor);
   shrunk_rect.set_height(shrunk_rect.height() - 1);
   background_fullscreen_hack_ = true;
   SetBoundsInternal(shrunk_rect, false);
 }
 
 }  // namespace views