For child windows, use parent coordinate system and bounds

ui/base/win/hwnd_util.cc

 // Copyright (c) 2011 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/base/win/hwnd_util.h"
 
 #include "base/i18n/rtl.h"
 #include "base/string_util.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
 namespace ui {
 
 namespace {
 
 // Adjust the window to fit, returning true if the window was resized or moved.
-bool AdjustWindowToFit(HWND hwnd, const RECT& bounds) {
+bool AdjustWindowToFit(HWND window, HWND parent, const RECT& bounds) {
   // Get the monitor.
   HMONITOR hmon = MonitorFromRect(&bounds, MONITOR_DEFAULTTONEAREST);
   if (!hmon) {
     NOTREACHED() << "Unable to find default monitor";
     // No monitor available.
     return false;
   }
 
   MONITORINFO mi;
   mi.cbSize = sizeof(mi);
   GetMonitorInfo(hmon, &mi);
   gfx::Rect window_rect(bounds);
-  gfx::Rect monitor_rect(mi.rcWork);
-  gfx::Rect new_window_rect = window_rect.AdjustToFit(monitor_rect);
+  gfx::Rect fit_bounds;
+  if (::GetWindowLong(window, GWL_STYLE) & WS_CHILD) {
+      RECT parent_rect;
+      ::GetWindowRect(parent, &parent_rect);
+      fit_bounds = parent_rect;
+      fit_bounds.Offset(-parent_rect.left, -parent_rect.top);
+  } else {
+      fit_bounds = mi.rcWork;
+  }
+  gfx::Rect new_window_rect = window_rect.AdjustToFit(fit_bounds);
   if (!new_window_rect.Equals(window_rect)) {
     // Window doesn't fit on monitor, move and possibly resize.
-    SetWindowPos(hwnd, 0, new_window_rect.x(), new_window_rect.y(),
+    SetWindowPos(window, 0, new_window_rect.x(), new_window_rect.y(),
                  new_window_rect.width(), new_window_rect.height(),
                  SWP_NOACTIVATE | SWP_NOZORDER);
     return true;
   } else {
     return false;
   }
 }
 
 }  // namespace
 
@@ skipping 106 matching lines @@
   // for the window.
   WINDOWINFO win_info = {0};
   win_info.cbSize = sizeof(WINDOWINFO);
   GetWindowInfo(window, &win_info);
 
   // Calculate the window size needed for the content size.
 
   if (!pref_is_client ||
       AdjustWindowRectEx(&window_bounds, win_info.dwStyle, FALSE,
                          win_info.dwExStyle)) {
-    if (!AdjustWindowToFit(window, window_bounds)) {
+    if (!AdjustWindowToFit(window, parent, window_bounds)) {
       // The window fits, reset the bounds.
       SetWindowPos(window, 0, window_bounds.left, window_bounds.top,
                    window_bounds.right - window_bounds.left,
                    window_bounds.bottom - window_bounds.top,
                    SWP_NOACTIVATE | SWP_NOZORDER);
     }  // else case, AdjustWindowToFit set the bounds for us.
   } else {
     NOTREACHED() << "Unable to adjust window to fit";
   }
 }
 
 void CheckWindowCreated(HWND hwnd) {
   if (!hwnd)
     LOG_GETLASTERROR(FATAL);
 }
 
 void ShowSystemMenu(HWND window, int screen_x, int screen_y) {
   UINT flags = TPM_LEFTBUTTON | TPM_RIGHTBUTTON | TPM_RETURNCMD;
   if (base::i18n::IsRTL())
     flags |= TPM_RIGHTALIGN;
   HMENU system_menu = GetSystemMenu(window, FALSE);
   int command = TrackPopupMenu(system_menu, flags, screen_x, screen_y, 0,
                                window, NULL);
   if (command)
     SendMessage(window, WM_SYSCOMMAND, command, 0);
 }
 
 }  // namespace ui