Fix Chrome overlapping an autohide taskbar in certain cases. Original patch by Satish Sampath (see http://codereview.chromium.org/1566054 ), r=me.

BUG=28042
TEST=Set taskbar to autohide and open a maximized Chrome window.  Toggle visibility of the Chrome window using the appropriate taskbar button, make sure that the taskbar stays up on screen after many attempts and never hides.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@44941 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 17 insertions, 0 deletions

diff --git a/views/window/window_win.cc b/views/window/window_win.cc
index d357768..554a9c7 100644
--- a/views/window/window_win.cc
+++ b/views/window/window_win.cc
@@ -761,6 +761,23 @@ LRESULT WindowWin::OnNCCalcSize(BOOL mode, LPARAM l_param) {
     // disappear.
     HMONITOR monitor = MonitorFromWindow(GetNativeView(),
                                          MONITOR_DEFAULTTONULL);
+    if (!monitor) {
+      // We might end up here if the window was previously minimized and the
+      // user clicks on the taskbar button to restore it in the previously
+      // maximized position. In that case WM_NCCALCSIZE is sent before the
+      // window coordinates are restored to their previous values, so our
+      // (left,top) would probably be (-32000,-32000) like all minimized
+      // windows. So the above MonitorFromWindow call fails, but if we check
+      // the window rect given with WM_NCCALCSIZE (which is our previous
+      // restored window position) we will get the correct monitor handle.
+      monitor = MonitorFromRect(client_rect, MONITOR_DEFAULTTONULL);
+      if (!monitor) {
+        // This is probably an extreme case that we won't hit, but if we don't
+        // intersect any monitor, let us not adjust the client rect since our
+        // window will not be visible anyway.
+        return 0;
+      }
+    }
     if (win_util::EdgeHasTopmostAutoHideTaskbar(ABE_LEFT, monitor))
       client_rect->left += win_util::kAutoHideTaskbarThicknessPx;
     if (win_util::EdgeHasTopmostAutoHideTaskbar(ABE_TOP, monitor)) {