Don't check autohide taskbar for WS_EX_TOPMOST when we are querying the autohide state.

chrome/browser/ui/views/chrome_views_delegate.cc

Index: chrome/browser/ui/views/chrome_views_delegate.cc
diff --git a/chrome/browser/ui/views/chrome_views_delegate.cc b/chrome/browser/ui/views/chrome_views_delegate.cc
index 3d66274647c07cd4dde40679454665a7c93361e0..a01d647e3c5bd7e8ad60d0d6da464a47f80b5a7c 100644
--- a/chrome/browser/ui/views/chrome_views_delegate.cc
+++ b/chrome/browser/ui/views/chrome_views_delegate.cc
@@ -99,14 +99,14 @@ PrefService* GetPrefsForWindow(const views::Widget* window) {
 }
 
 #if defined(OS_WIN)
-bool MonitorHasTopmostAutohideTaskbarForEdge(UINT edge, HMONITOR monitor) {
+bool MonitorHasAutohideTaskbarForEdge(UINT edge, HMONITOR monitor) {
   APPBARDATA taskbar_data = { sizeof(APPBARDATA), NULL, 0, edge };
   taskbar_data.hWnd = ::GetForegroundWindow();
 
   // TODO(robliao): Remove ScopedTracker below once crbug.com/462368 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "462368 MonitorHasTopmostAutohideTaskbarForEdge"));
+          "462368 MonitorHasAutohideTaskbarForEdge"));
 
   // MSDN documents an ABM_GETAUTOHIDEBAREX, which supposedly takes a monitor
   // rect and returns autohide bars on that monitor.  This sounds like a good
@@ -139,8 +139,7 @@ bool MonitorHasTopmostAutohideTaskbarForEdge(UINT edge, HMONITOR monitor) {
       taskbar = taskbar_data.hWnd;
   }
 
-  if (::IsWindow(taskbar) &&
-      (GetWindowLong(taskbar, GWL_EXSTYLE) & WS_EX_TOPMOST)) {

[ananta, 2016/11/30 02:16:18]

Found this patch from 2+ years ago which had this code. Could not find log
beyond that.

[Peter Kasting, 2016/11/30 07:30:30]

You didn't link to the patch, but I tracked this down further.  (Just gotta be
persistent about tracing through git...)

It was added intentionally here:

https://codereview.chromium.org/66055

See also https://bugs.chromium.org/p/chromium/issues/detail?id=20#c135 , and
maybe https://bugs.chromium.org/p/chromium/issues/detail?id=20#c121 .

I'd like to understand this stuff more closely before OKing removing this.  It
seems like we don't want non-topmost autohide bars to reserve any space, and I'm
worried this would regress that.

[ananta, 2016/11/30 20:37:47]

I found this link on msdn
https://msdn.microsoft.com/en-us/library/windows/desktop/bb787947(v=vs.85).aspx
which states that the option to have a not on top taskbar does not exist
anymore. (From Win 7+) that is. We don't care about vista or XP anymore. With
this it should be safe to remove the topmost check?

+  if (::IsWindow(taskbar)) {
     if (MonitorFromWindow(taskbar, MONITOR_DEFAULTTONEAREST) == monitor)
       return true;
     // In some cases like when the autohide taskbar is on the left of the
@@ -159,13 +158,13 @@ int GetAppbarAutohideEdgesOnWorkerThread(HMONITOR monitor) {
   DCHECK(monitor);
 
   int edges = 0;
-  if (MonitorHasTopmostAutohideTaskbarForEdge(ABE_LEFT, monitor))
+  if (MonitorHasAutohideTaskbarForEdge(ABE_LEFT, monitor))
     edges |= views::ViewsDelegate::EDGE_LEFT;
-  if (MonitorHasTopmostAutohideTaskbarForEdge(ABE_TOP, monitor))
+  if (MonitorHasAutohideTaskbarForEdge(ABE_TOP, monitor))
     edges |= views::ViewsDelegate::EDGE_TOP;
-  if (MonitorHasTopmostAutohideTaskbarForEdge(ABE_RIGHT, monitor))
+  if (MonitorHasAutohideTaskbarForEdge(ABE_RIGHT, monitor))
     edges |= views::ViewsDelegate::EDGE_RIGHT;
-  if (MonitorHasTopmostAutohideTaskbarForEdge(ABE_BOTTOM, monitor))
+  if (MonitorHasAutohideTaskbarForEdge(ABE_BOTTOM, monitor))
     edges |= views::ViewsDelegate::EDGE_BOTTOM;
   return edges;
 }