X11: Treat a minimized window as visible

This is for consistency with Windows and allows minimized windows to be
activated.

BUG=924075
R=sky,fbeaufort

Change-Id: Ic86ffba47805b2ba4f5c8f049cdccd2e75be8d9b
Reviewed-on: https://chromium-review.googlesource.com/c/1437263
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626192}

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

@@ -518,7 +518,7 @@ void DesktopWindowTreeHostX11::Show(ui::WindowShowState show_state,
   if (compositor())
     SetVisible(true);
 
-  if (!IsVisible())
+  if (!window_mapped_in_client_ || IsMinimized())
     MapWindow(show_state);
 
   switch (show_state) {
@@ -547,7 +547,10 @@ void DesktopWindowTreeHostX11::Show(ui::WindowShowState show_state,
 }
 
 bool DesktopWindowTreeHostX11::IsVisible() const {
-  return window_mapped_in_client_ && !IsMinimized();
+  // On Windows, IsVisible() returns true for minimized windows.  On X11, a
+  // minimized window is not mapped, so an explicit IsMinimized() check is
+  // necessary.
+  return window_mapped_in_client_ || IsMinimized();
 }
 
 void DesktopWindowTreeHostX11::SetSize(const gfx::Size& requested_size) {
@@ -762,7 +765,6 @@ void DesktopWindowTreeHostX11::Activate() {
     // after an Activate(), so just set this state now.
     has_pointer_focus_ = false;
     has_window_focus_ = true;
-    // window_mapped_in_client_ == true based on the IsVisible() check above.
     window_mapped_in_server_ = true;
     XSetErrorHandler(old_error_handler);
   }
@@ -816,7 +818,7 @@ void DesktopWindowTreeHostX11::Maximize() {
 
   // Some WMs do not respect maximization hints on unmapped windows, so we
   // save this one for later too.
-  should_maximize_after_map_ = !IsVisible();
+  should_maximize_after_map_ = !window_mapped_in_client_;
 
   // When we are in the process of requesting to maximize a window, we can
   // accurately keep track of our restored bounds instead of relying on the