[ios] Suspend/Unsuspend compositor in BrowserCompositorIOS

This CL adds private methods below to BrowserCompositorIOS to manage
compositor when it’s created and destroyed.

void Suspend();
void Unsuspend();
void InvalidateSurface();

Like BrowserCompositorMac, it calls Suspend() and Unsuspend() to
control CompositorLock when the compositor is created.
It also adds InvalidateSurface() to reset surface information when
the compositor is destroyed.

In this CL, RenderWidgetHostViewPresentationFeedbackBrowserTest.Show
is enabled.

Bug: 1413706, 1467641
Change-Id: Id800de340fb892348519f2420679f3b856ae503b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4935970
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1209799}

content/browser/renderer_host/browser_compositor_ios.h

@@ -160,6 +160,10 @@ class CONTENT_EXPORT BrowserCompositorIOS : public DelegatedFrameHostClient,
                      float scale_factor,
                      const gfx::DisplayColorSpaces& display_color_spaces);
 
+  void InvalidateSurface();
+  void Suspend();
+  void Unsuspend();
+
   // Weak pointer to the layer supplied and reset via SetParentUiLayer. |this|
   // is an observer of |parent_ui_layer_|, to ensure that |parent_ui_layer_|
   // always be valid when non-null. The UpdateState function will re-parent
@@ -190,6 +194,7 @@ class CONTENT_EXPORT BrowserCompositorIOS : public DelegatedFrameHostClient,
   gfx::Size size_pixels_;
   float scale_factor_ = 1.f;
   gfx::DisplayColorSpaces display_color_spaces_;
+  std::unique_ptr<ui::CompositorLock> compositor_suspended_lock_;
 
   base::WeakPtrFactory<BrowserCompositorIOS> weak_factory_;
 };

content/browser/renderer_host/browser_compositor_ios.mm

@@ -224,6 +224,7 @@
   if (state_ == HasOwnCompositor) {
     compositor_->SetRootLayer(nullptr);
     compositor_.reset();
+    InvalidateSurface();
   }
 
   // The compositor is now detached. If this is the target state, we're done.
@@ -249,12 +250,14 @@
         context_factory->AllocateFrameSinkId(), context_factory,
         base::SingleThreadTaskRunner::GetCurrentDefault(),
         ui::IsPixelCanvasRecordingEnabled());
+    Suspend();
     display::ScreenInfo current = client_->GetCurrentScreenInfo();
     UpdateSurface(dfh_size_pixels_, current.device_scale_factor,
                   current.display_color_spaces);
     compositor_->SetRootLayer(root_layer_.get());
     compositor_->SetBackgroundColor(background_color_);
     compositor_->SetAcceleratedWidget(accelerated_widget_);
+    Unsuspend();
     state_ = HasOwnCompositor;
   }
   DCHECK_EQ(state_, new_state);
@@ -433,4 +436,21 @@
   }
 }
 
+void BrowserCompositorIOS::InvalidateSurface() {
+  size_pixels_ = gfx::Size();
+  scale_factor_ = 1.f;
+  local_surface_id_allocator_.Invalidate();
+}
+
+void BrowserCompositorIOS::Suspend() {
+  DCHECK(compositor_);
+  // Requests a compositor lock without a timeout.
+  compositor_suspended_lock_ =
+      compositor_->GetCompositorLock(nullptr, base::TimeDelta());
+}
+
+void BrowserCompositorIOS::Unsuspend() {
+  compositor_suspended_lock_ = nullptr;
+}
+
 }  // namespace content

content/browser/renderer_host/render_widget_host_view_ios.mm

@@ -570,8 +570,18 @@ - (void)updateView:(UIScrollView*)view {
     RequestSuccessfulPresentationTimeFromHostOrDelegate(
         blink::mojom::RecordContentToVisibleTimeRequestPtr
             visible_time_request) {
-  host()->RequestSuccessfulPresentationTimeForNextFrame(
-      std::move(visible_time_request));
+  // No state transition here so don't use
+  // has_saved_frame_before_state_transition.
+  if (browser_compositor_->GetDelegatedFrameHost()->HasSavedFrame()) {
+    // If the frame for the renderer is already available, then the
+    // tab-switching time is the presentation time for the browser-compositor.
+    browser_compositor_->GetDelegatedFrameHost()
+        ->RequestSuccessfulPresentationTimeForNextFrame(
+            std::move(visible_time_request));
+  } else {
+    host()->RequestSuccessfulPresentationTimeForNextFrame(
+        std::move(visible_time_request));
+  }
 }
 void RenderWidgetHostViewIOS::
     CancelSuccessfulPresentationTimeRequestForHostAndDelegate() {

testing/buildbot/filters/ios.content_browsertests.filter

@@ -105,8 +105,6 @@
 -RenderWidgetHostSitePerProcessTest.BrowserClosesSelectPopup
 -RenderWidgetHostTouchEmulatorBrowserTest.TouchEmulatorPinchWithGestureFling
 -RenderWidgetHostViewChildFrameBrowserTest.VisualPropertiesPropagation_RootWindowSegments
--RenderWidgetHostViewPresentationFeedbackBrowserTest.Show
--RenderWidgetHostViewPresentationFeedbackBrowserTest.ShowWhileCapturing
 -SRC_ClearKey/EncryptedMediaTest.Playback_VideoOnly_WebM_VP9Profile2/0
 -ScrollBehaviorBrowserTest.InstantScriptScrollAdjustsSmoothWheelScroll
 -ScrollBehaviorBrowserTest.SmoothWheelScrollCompletesWithScriptedMirror