MacViews: Attach child windows when parent is on the screen.

ui/views/cocoa/views_nswindow_delegate.mm

 // Copyright 2014 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.
 
 #import "ui/views/cocoa/views_nswindow_delegate.h"
 
 #include "base/logging.h"
 #import "ui/views/cocoa/bridged_content_view.h"
 #import "ui/views/cocoa/bridged_native_widget.h"
 #include "ui/views/widget/native_widget_mac.h"
@@ skipping 17 matching lines @@
 }
 
 - (void)setCursor:(NSCursor*)newCursor {
   if (cursor_.get() == newCursor)
     return;
 
   cursor_.reset([newCursor retain]);
   [parent_->ns_window() resetCursorRects];
 }
 
-- (void)onWindowOrderWillChange:(NSWindowOrderingMode)orderingMode {
-  parent_->OnVisibilityChangedTo(orderingMode != NSWindowOut);

[tapted, 2016/06/17 04:33:05]

So you're correct that this shouldn't be calling OnVisibilityChangedTo(true) --
if [NSWindow visible] is still reporting NO, then that's likely to screw up the
child window relationships. But this was added  to ensure we have a valid
`paint` before the window becomes visible -- we still need that hook. i.e. it's
still a bug that windows come out of minimize "blank", and that windows appear
on screen first with blank background before the content appears. We need to
generalize the stuff that's done for modal sheets in void
BridgedNativeWidget::ShowAsModalSheet() -- the code there ensures the window
contents are available. We need to do the same for windows first appearing on
screen, and for windows coming out of minimize. Do you want to give this a go?

[kirr, 2016/06/20 16:15:54]

Sorry for delay.
I've checked blank window blinking one more time.

First thing is that now there is a blinking. So removing this line should not
change anything to worse.

Also I've tried to fix it as you say, by showing a layer and waiting for a frame
and then change window visibility.
Here is a draft
https://gist.github.com/anonymous/1607657661087e0ca73e0352495c47cf

It's working. But I think that it's better to fix it as render_widget_host_view
does. It leaves the CALayer visible and suspend compositor. Maybe some aura code
expect that native widget visibility is equal to layer visibility. I think it's
better to try and see if tests fails.

So, can we commit this CL as it is (maybe with test)? And fix blinking in
another one.

-}
-
 - (void)onWindowOrderChanged:(NSNotification*)notification {
   parent_->OnVisibilityChanged();
 }
 
 - (void)onWindowWillDisplay {
   parent_->OnVisibilityChangedTo(true);

[tapted, 2016/06/21 00:08:35]

Let's make this parent_->OnVisibilityChanged() as well and remove
OnVisibilityChangedTo from the API. If the bug is that reparenting fails when
the argument to OnVisibilityChangedTo doesn't match [window_ isVisible] then we
should make it impossible for that to be triggered.

[kirr, 2016/06/21 16:33:47]

Done. I've also removed [NSWindow display] overload.
Seems like it's not calling on os x 10.11 at least in views_unittests.

 }
 
 - (void)sheetDidEnd:(NSWindow*)sheet
          returnCode:(NSInteger)returnCode
         contextInfo:(void*)contextInfo {
   [sheet orderOut:nil];
   parent_->OnWindowWillClose();
 }
 
 - (BOOL)shouldRepostPendingLeftMouseDown:(NSPoint)locationInWindow {
@@ skipping 78 matching lines @@
             usingRect:(NSRect)defaultSheetLocation {
   // As per NSWindowDelegate documentation, the origin indicates the top left
   // point of the host frame in window coordinates. The width changes the
   // animation from vertical to trapezoid if it is smaller than the width of the
   // dialog. The height is ignored but should be set to zero.
   return NSMakeRect(0, [self nativeWidgetMac]->SheetPositionY(),
                     NSWidth(defaultSheetLocation), 0);
 }
 
 @end