MacViews: Fix flashing of opaque non-modal windows on display.

ui/views/cocoa/bridged_native_widget.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/bridged_native_widget.h"
 
 #import <objc/runtime.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 553 matching lines @@
   // If the parent (or an ancestor) is hidden, return and wait for it to become
   // visible.
   if (parent() && !parent()->IsVisibleParent())
     return;
 
   if (native_widget_mac_->IsWindowModalSheet()) {
     ShowAsModalSheet();
     return;
   }
 
+  // Non-modal windows are not animated. Hence opaque non-modal windows can
+  // appear with a "flash" if they are made visible before the frame from the
+  // compositor arrives. To get around this, set the alpha value of the window
+  // to 0, till we receive the correct frame from the compositor. Also, ignore
+  // mouse clicks till then.
+  // TODO(karandeepb): Investigate whether similar technique is needed for other
+  // dialog types.
+  if ([window_ isOpaque] && !native_widget_mac_->GetWidget()->IsModal()) {
+    initial_visibility_suppressed_ = true;
+    [window_ setAlphaValue:0.0];
+    [window_ setIgnoresMouseEvents:YES];
+  }
+
   if (new_state == SHOW_AND_ACTIVATE_WINDOW) {
     [window_ makeKeyAndOrderFront:nil];
     [NSApp activateIgnoringOtherApps:YES];
   } else {
     // ui::SHOW_STATE_INACTIVE is typically used to avoid stealing focus from a
     // parent window. So, if there's a parent, order above that. Otherwise, this
     // will order above all windows at the same level.
     NSInteger parent_window_number = 0;
     if (parent_)
       parent_window_number = [parent_->GetNSWindow() windowNumber];
@@ skipping 509 matching lines @@
   *timebase = base::TimeTicks();
   *interval = base::TimeDelta();
 }
 
 void BridgedNativeWidget::AcceleratedWidgetSwapCompleted() {
   // Ignore frames arriving "late" for an old size. A frame at the new size
   // should arrive soon.
   if (!compositor_widget_->HasFrameOfSize(GetClientAreaSize()))
     return;
 
+  if (initial_visibility_suppressed_) {
+    initial_visibility_suppressed_ = false;
+    [window_ setAlphaValue:1.0];
+    [window_ setIgnoresMouseEvents:NO];
+  }
+
   if (invalidate_shadow_on_frame_swap_) {
     invalidate_shadow_on_frame_swap_ = false;
     [window_ invalidateShadow];
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // BridgedNativeWidget, BridgedNativeWidgetOwner:
 
 NSWindow* BridgedNativeWidget::GetNSWindow() {
@@ skipping 252 matching lines @@
   [bridged_view_ setMouseDownCanMoveWindow:draggable];
   // AppKit will not update its cache of mouseDownCanMoveWindow unless something
   // changes. Previously we tried adding an NSView and removing it, but for some
   // reason it required reposting the mouse-down event, and didn't always work.
   // Calling the below seems to be an effective solution.
   [window_ setMovableByWindowBackground:NO];
   [window_ setMovableByWindowBackground:YES];
 }
 
 }  // namespace views