MacViews: Do not block UI thread waiting for translucent windows

For translucent windows, don't do any CATransaction synchronization
until after the first frame has been received.

This allows us to avoid blocking the UI thread when entering the first
keystrokes in the omnibox.

While in the neighborhood, delete the dead code for using alpha to
make windows appear atomically.

Bug: 712268
Change-Id: I71cab1c1c598adc34542b6990d8f9112eda8be4f
Reviewed-on: https://chromium-review.googlesource.com/1135891
Commit-Queue: ccameron <ccameron@chromium.org>
Reviewed-by: Sidney San Martín <sdy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574771}

ui/views/cocoa/bridged_native_widget.h

@@ -337,15 +337,14 @@ class VIEWS_EXPORT BridgedNativeWidget
   // Whether to animate the window (when it is appropriate to do so).
   bool animate_ = true;
 
+  // If true, then ignore interactions with CATransactionCoordinator until the
+  // first frame arrives.
+  bool ca_transaction_sync_suppressed_ = false;
+
   // If true, the window has been made visible or changed shape and the window
   // shadow needs to be invalidated when a frame is received for the new shape.
   bool invalidate_shadow_on_frame_swap_ = false;
 
-  // Whether the window's visibility is suppressed currently. For opaque non-
-  // modal windows, the window's alpha value is set to 0, till the frame from
-  // the compositor arrives to avoid "blinking".
-  bool initial_visibility_suppressed_ = false;
-
   AssociatedViews associated_views_;
 
   DISALLOW_COPY_AND_ASSIGN(BridgedNativeWidget);

ui/views/cocoa/bridged_native_widget.mm

@@ -491,6 +491,7 @@ void BridgedNativeWidget::SetVisibilityState(WindowVisibilityState new_state) {
 
   DCHECK(wants_to_be_visible_);
 
+  if (!ca_transaction_sync_suppressed_)
     ui::CATransactionCoordinator::Get().Synchronize();
 
   // If the parent (or an ancestor) is hidden, return and wait for it to become
@@ -503,24 +504,6 @@ void BridgedNativeWidget::SetVisibilityState(WindowVisibilityState new_state) {
     return;
   }
 
-  // TODO(https://crbug.com/682825): Delete this during cleanup.
-  // 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. Also check for an active task runner on the
-  // WindowResizeHelperMac instance to ensure visibility is only suppressed when
-  // there is an active GPU process.
-  // TODO(karandeepb): Investigate whether similar technique is needed for other
-  // dialog types.
-  if (false && layer() && [window_ isOpaque] && !window_visible_ &&
-      !native_widget_mac_->GetWidget()->IsModal() &&
-      ui::WindowResizeHelperMac::Get()->task_runner()) {
-    initial_visibility_suppressed_ = true;
-    [window_ setAlphaValue:0.0];
-    [window_ setIgnoresMouseEvents:YES];
-  }
-
   if (new_state == SHOW_AND_ACTIVATE_WINDOW) {
     [window_ makeKeyAndOrderFront:nil];
     [NSApp activateIgnoringOtherApps:YES];
@@ -900,6 +883,12 @@ void BridgedNativeWidget::CreateLayer(ui::LayerType layer_type,
                                                            : SK_ColorWHITE);
   layer()->SetFillsBoundsOpaquely(!translucent);
 
+  // Don't block waiting for the initial frame of transparent windows. This
+  // allows us to avoid blocking on the UI thread e.g, while typing in the
+  // omnibox.
+  // https://crbug.com/712268
+  ca_transaction_sync_suppressed_ = translucent;
+
   // Use the regular window background for window modal sheets. The layer() will
   // still paint over most of it, but the native -[NSApp beginSheet:] animation
   // blocks the UI thread, so there's no way to invalidate the shadow to match
@@ -989,9 +978,13 @@ void BridgedNativeWidget::ReparentNativeView(NSView* native_view,
 // BridgedNativeWidget, ui::CATransactionObserver
 
 bool BridgedNativeWidget::ShouldWaitInPreCommit() {
-  return window_visible_ &&
-         (!compositor_ ||
-          !compositor_->widget()->HasFrameOfSize(GetClientAreaSize()));
+  if (!window_visible_)
+    return false;
+  if (ca_transaction_sync_suppressed_)
+    return false;
+  if (!compositor_)
+    return false;
+  return !compositor_->widget()->HasFrameOfSize(GetClientAreaSize());
 }
 
 base::TimeDelta BridgedNativeWidget::PreCommitTimeout() {
@@ -1076,11 +1069,8 @@ void BridgedNativeWidget::AcceleratedWidgetCALayerParamsUpdated() {
   if (ca_layer_params)
     display_ca_layer_tree_->UpdateCALayerTree(*ca_layer_params);
 
-  if (initial_visibility_suppressed_) {
-    initial_visibility_suppressed_ = false;
-    [window_ setAlphaValue:1.0];
-    [window_ setIgnoresMouseEvents:NO];
-  }
+  if (ca_transaction_sync_suppressed_)
+    ca_transaction_sync_suppressed_ = false;
 
   if (invalidate_shadow_on_frame_swap_) {
     invalidate_shadow_on_frame_swap_ = false;
@@ -1281,6 +1271,7 @@ void BridgedNativeWidget::UpdateLayerProperties() {
   gfx::Size size_in_dip = GetClientAreaSize();
   gfx::Size size_in_pixel = ConvertSizeToPixel(scale_factor, size_in_dip);
 
+  if (!ca_transaction_sync_suppressed_)
     ui::CATransactionCoordinator::Get().Synchronize();
 
   layer()->SetBounds(gfx::Rect(size_in_dip));