On Windows 8 when a metro application is snapped running desktop application windows are resized as

chrome/browser/ui/views/frame/browser_frame_win.cc

Index: chrome/browser/ui/views/frame/browser_frame_win.cc
===================================================================
--- chrome/browser/ui/views/frame/browser_frame_win.cc	(revision 143310)
+++ chrome/browser/ui/views/frame/browser_frame_win.cc	(working copy)
@@ -6,7 +6,6 @@
 
 #include <dwmapi.h>
 #include <shellapi.h>
-
 #include <set>
 
 #include "base/command_line.h"
@@ -31,6 +30,7 @@
 #include "googleurl/src/gurl.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/simple_menu_model.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/theme_provider.h"
@@ -95,7 +95,8 @@
       browser_view_(browser_view),
       browser_frame_(browser_frame),
       system_menu_delegate_(new SystemMenuModelDelegate(browser_view,
-          browser_view->browser())) {
+          browser_view->browser())),
+      cached_minimize_button_x_delta_(0) {
   if (base::win::IsMetroProcess()) {
     browser_view->SetWindowSwitcherButton(
         MakeWindowSwitcherButton(this, browser_view->IsOffTheRecord()));
@@ -250,6 +251,12 @@
   views::NativeWidgetWin::Close();
 }
 
+void BrowserFrameWin::OnActivate(UINT action, BOOL minimized, HWND window) {
+  if (action != WA_INACTIVE)
+    CacheMinimizeButtonDelta();
+  views::NativeWidgetWin::OnActivate(action, minimized, window);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserFrameWin, NativeBrowserFrame implementation:
 
@@ -275,15 +282,28 @@
 }
 
 int BrowserFrameWin::GetMinimizeButtonOffset() const {
-  TITLEBARINFOEX titlebar_info;
+  // The WM_GETTITLEBARINFOEX message can fail if we are not active/visible.
+  TITLEBARINFOEX titlebar_info = {0};
   titlebar_info.cbSize = sizeof(TITLEBARINFOEX);
-  SendMessage(GetNativeView(), WM_GETTITLEBARINFOEX, 0, (WPARAM)&titlebar_info);
+  BOOL ret = SendMessage(GetNativeView(), WM_GETTITLEBARINFOEX, 0,

[sky, 2012/06/21 18:13:40]

Remove 'ret' since as you said its always true ad you don't use it.

[ananta, 2012/06/21 18:27:46]

Done.

+                         reinterpret_cast<WPARAM>(&titlebar_info));
 
   CPoint minimize_button_corner(titlebar_info.rgrect[2].left,
                                 titlebar_info.rgrect[2].top);
   MapWindowPoints(HWND_DESKTOP, GetNativeView(), &minimize_button_corner, 1);
 
-  return minimize_button_corner.x;
+  if (minimize_button_corner.x)
+    return minimize_button_corner.x;
+
+  DCHECK(cached_minimize_button_x_delta_);
+
+  RECT client_rect = {0};
+  GetClientRect(&client_rect);
+
+  if (base::i18n::IsRTL())
+    return cached_minimize_button_x_delta_;
+  else
+    return client_rect.right - cached_minimize_button_x_delta_;
 }
 
 void BrowserFrameWin::TabStripDisplayModeChanged() {
@@ -505,7 +525,24 @@
       UTF8ToWide(current_tab->GetURL().spec()));
 }
 
+void BrowserFrameWin::CacheMinimizeButtonDelta() {
+  int minimize_offset = GetMinimizeButtonOffset();

[sky, 2012/06/21 18:13:40]

The way you have the code now you're only going to cache the first time through,
subsequently this never returns 0 (since it uses the cached value).

[ananta, 2012/06/21 18:27:46]

Thanks for catching this. Isolated the WM_GETTITLEBARINFO stuff into a helper
functionGetMinimizeButtonOffsetFromWindows which is called from here and
GetMinimizeButtonOffset.

+  if (!minimize_offset)
+    return;
 
+  RECT rect = {0};
+  GetClientRect(&rect);
+  // Calculate and cache the value of the minimize button delta, i.e. the
+  // offset to be applied to the left or right edge of the client rect
+  // depending on whether the language is RTL or not.
+  // This cached value is only used if the WM_GETTITLEBARINFOEX message fails
+  // to get the offset of the minimize button.
+  if (base::i18n::IsRTL())
+    cached_minimize_button_x_delta_ = minimize_offset;
+  else
+    cached_minimize_button_x_delta_ = rect.right - minimize_offset;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserFrame, public: