mac: Don't use CATransactionObserver for RWHVMac in views mode

The surface sync APIs are used in views mode (becaused we use a single
ui::Compositor).

Delete some of the now-dead code from RWHVMac (it has deep roots which
still need to go).

Change-Id: I6f065288c27d3ebecf113494751bfc8dfd199fd7
Reviewed-on: https://chromium-review.googlesource.com/1105024Reviewed-by: Erik Chen <erikchen@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568218}

content/browser/renderer_host/browser_compositor_view_mac.h

@@ -140,8 +140,6 @@ class CONTENT_EXPORT BrowserCompositorMac : public DelegatedFrameHostClient,
 
   void DidNavigate();
 
-  void BeginPauseForFrame(bool auto_resize_enabled);
-  void EndPauseForFrame();
   bool ShouldContinueToPauseForFrame() const;
 
   bool ForceNewSurfaceForTesting();
@@ -222,18 +220,6 @@ class CONTENT_EXPORT BrowserCompositorMac : public DelegatedFrameHostClient,
   gfx::Size dfh_size_dip_;
   display::Display dfh_display_;
 
-  // Used to disable screen updates while resizing (because frames are drawn in
-  // the GPU process, they can end up appearing on-screen before our window
-  // resizes).
-  enum class RepaintState {
-    // No repaint in progress.
-    None,
-    // Synchronously waiting for a new frame.
-    Paused,
-    // Screen updates are disabled while a new frame is swapped in.
-    ScreenUpdatesDisabled,
-  } repaint_state_ = RepaintState::None;
-  bool repaint_auto_resize_enabled_ = false;
   bool is_first_navigation_ = true;
 
   base::WeakPtrFactory<BrowserCompositorMac> weak_factory_;

content/browser/renderer_host/browser_compositor_view_mac.mm

@@ -536,19 +536,6 @@ void BrowserCompositorMac::OnFirstSurfaceActivation(
     return;
 
   recyclable_compositor_->Unsuspend();
-
-  // Disable screen updates until the frame of the new size appears (because the
-  // content is drawn in the GPU process, it may change before we want it to).
-  if (repaint_state_ == RepaintState::Paused) {
-    bool compositor_is_nsview_size =
-        recyclable_compositor_->pixel_size() == dfh_size_pixels_ &&
-        recyclable_compositor_->scale_factor() ==
-            dfh_display_.device_scale_factor();
-    if (compositor_is_nsview_size || repaint_auto_resize_enabled_) {
-      NSDisableScreenUpdates();
-      repaint_state_ = RepaintState::ScreenUpdatesDisabled;
-    }
-  }
 }
 
 void BrowserCompositorMac::OnBeginFrame(base::TimeTicks frame_time) {
@@ -578,17 +565,6 @@ void BrowserCompositorMac::DidReceiveFirstFrameAfterNavigation() {
   client_->DidReceiveFirstFrameAfterNavigation();
 }
 
-void BrowserCompositorMac::BeginPauseForFrame(bool auto_resize_enabled) {
-  repaint_auto_resize_enabled_ = auto_resize_enabled;
-  repaint_state_ = RepaintState::Paused;
-}
-
-void BrowserCompositorMac::EndPauseForFrame() {
-  if (repaint_state_ == RepaintState::ScreenUpdatesDisabled)
-    NSEnableScreenUpdates();
-  repaint_state_ = RepaintState::None;
-}
-
 bool BrowserCompositorMac::ShouldContinueToPauseForFrame() const {
   if (state_ == UseParentLayerCompositor)
     return false;

content/browser/renderer_host/render_widget_host_view_mac.h

@@ -155,7 +155,6 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   gfx::AcceleratedWidget AccessibilityGetAcceleratedWidget() override;
   base::Optional<SkColor> GetBackgroundColor() const override;
 
-  bool ShouldContinueToPauseForFrame() override;
   void SetParentUiLayer(ui::Layer* parent_ui_layer) override;
   gfx::Vector2d GetOffsetFromRootSurface() override;
   gfx::Rect GetBoundsInRootWindow() override;
@@ -299,8 +298,6 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   // RenderWidgetHostImpl as well.
   void UpdateNSViewAndDisplayProperties();
 
-  void PauseForPendingResizeOrRepaintsAndDraw();
-
   // RenderWidgetHostNSViewClient implementation.
   BrowserAccessibilityManager* GetRootBrowserAccessibilityManager() override;
   void OnNSViewSyncIsRenderViewHost(bool* is_render_view) override;
@@ -499,9 +496,6 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   // Indicates if the page is loading.
   bool is_loading_;
 
-  // Whether it's allowed to pause waiting for a new frame.
-  bool allow_pause_for_resize_or_repaint_;
-
   // True when this view acts as a platform view hack for a
   // RenderWidgetHostViewGuest.
   bool is_guest_view_hack_;

content/browser/renderer_host/render_widget_host_view_mac.mm

@@ -140,7 +140,6 @@ RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget,
       page_at_minimum_scale_(true),
       mouse_wheel_phase_handler_(this),
       is_loading_(false),
-      allow_pause_for_resize_or_repaint_(true),
       is_guest_view_hack_(is_guest_view_hack),
       gesture_provider_(ui::GetGestureProviderConfig(
                             ui::GestureProviderConfigType::CURRENT_PLATFORM),
@@ -198,10 +197,12 @@ RenderWidgetHostViewMac::RenderWidgetHostViewMac(RenderWidgetHost* widget,
   // startup raciness and decrease latency.
   needs_begin_frames_ = needs_begin_frames;
   UpdateNeedsBeginFramesInternal();
+  if (features::IsViewsBrowserCocoa())
     ui::CATransactionCoordinator::Get().AddPreCommitObserver(this);
 }
 
 RenderWidgetHostViewMac::~RenderWidgetHostViewMac() {
+  if (features::IsViewsBrowserCocoa())
     ui::CATransactionCoordinator::Get().RemovePreCommitObserver(this);
 }
 
@@ -230,7 +231,8 @@ void RenderWidgetHostViewMac::SetDelegate(
 }
 
 void RenderWidgetHostViewMac::SetAllowPauseForResizeOrRepaint(bool allow) {
-  allow_pause_for_resize_or_repaint_ = allow;
+  // TODO: Remove SetAllowPauseForResizeOrRepaint and SetAllowOtherViews, since
+  // they aren't used anymore.
 }
 
 ui::TextInputType RenderWidgetHostViewMac::GetTextInputType() {
@@ -332,6 +334,8 @@ void RenderWidgetHostViewMac::UpdateNSViewAndDisplayProperties() {
       LOG(ERROR) << "Failed to create display link.";
     }
   }
+
+  if (features::IsViewsBrowserCocoa())
     ui::CATransactionCoordinator::Get().Synchronize();
 
   // During auto-resize it is the responsibility of the caller to ensure that
@@ -368,7 +372,6 @@ void RenderWidgetHostViewMac::Show() {
   // If there is not a frame being currently drawn, kick one, so that the below
   // pause will have a frame to wait on.
   host()->RequestRepaintForTesting();
-  PauseForPendingResizeOrRepaintsAndDraw();
 }
 
 void RenderWidgetHostViewMac::Hide() {
@@ -553,7 +556,7 @@ void RenderWidgetHostViewMac::OnTextSelectionChanged(
 }
 
 bool RenderWidgetHostViewMac::ShouldWaitInPreCommit() {
-  return ShouldContinueToPauseForFrame();
+  return browser_compositor_->ShouldContinueToPauseForFrame();
 }
 
 base::TimeDelta RenderWidgetHostViewMac::PreCommitTimeout() {
@@ -950,14 +953,6 @@ bool RenderWidgetHostViewMac::GetCachedFirstRectForCharacterRange(
   return true;
 }
 
-bool RenderWidgetHostViewMac::ShouldContinueToPauseForFrame() {
-  // Only pause for frames when drawing through a separate ui::Compositor.
-  if (display_only_using_parent_ui_layer_)
-    return false;
-
-  return browser_compositor_->ShouldContinueToPauseForFrame();
-}
-
 void RenderWidgetHostViewMac::FocusedNodeChanged(
     bool is_editable_node,
     const gfx::Rect& node_bounds_in_screen) {
@@ -1299,24 +1294,6 @@ void RenderWidgetHostViewMac::SetTextInputActive(bool active) {
     password_input_enabler_.reset();
 }
 
-void RenderWidgetHostViewMac::PauseForPendingResizeOrRepaintsAndDraw() {
-  return;  // TODO(https://crbug.com/682825): Delete this during cleanup.
-
-  if (!host() || !browser_compositor_ || host()->is_hidden()) {
-    return;
-  }
-
-  // Pausing for one view prevents others from receiving frames.
-  // This may lead to large delays, causing overlaps. See crbug.com/352020.
-  if (!allow_pause_for_resize_or_repaint_)
-    return;
-
-  // Wait for a frame of the right size to come in.
-  browser_compositor_->BeginPauseForFrame(host()->auto_resize_enabled());
-  host()->PauseForPendingResizeOrRepaints();
-  browser_compositor_->EndPauseForFrame();
-}
-
 // static
 viz::FrameSinkId
 RenderWidgetHostViewMac::AllocateFrameSinkIdForGuestViewHack() {
@@ -1385,14 +1362,8 @@ void RenderWidgetHostViewMac::OnNSViewBoundsInWindowChanged(
     view_bounds_in_window_dip_.set_size(view_bounds_in_window_dip.size());
   }
 
-  if (view_size_changed) {
+  if (view_size_changed)
     UpdateNSViewAndDisplayProperties();
-    // Wait for the frame that WasResize might have requested. If the view is
-    // being made visible at a new size, then this call will have no effect
-    // because the view widget is still hidden, and the pause call in WasShown
-    // will have this effect for us.
-    PauseForPendingResizeOrRepaintsAndDraw();
-  }
 }
 
 void RenderWidgetHostViewMac::OnNSViewWindowFrameInScreenChanged(