Hide fullscreen rotation jank

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 2da5ad962dfed375abda9c138e1ef5a92d183fbd..39f467ad7625a9894902e9625cea13ff146090b6 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -565,6 +565,12 @@ void RenderWidgetHostViewAndroid::WasResized() {
   host_->WasResized();
 }
 
+void RenderWidgetHostViewAndroid::OnFullscreenStateChanged(
+    bool entered_fullscreen) {
+  web_contents_is_fullscreen_ = entered_fullscreen;
+  UpdateFullscreenStateAndEvictFrameIfNeeded();
+}
+
 void RenderWidgetHostViewAndroid::SetSize(const gfx::Size& size) {
   // Ignore the given size as only the Java code has the power to
   // resize the view on Android.
@@ -1184,6 +1190,65 @@ void RenderWidgetHostViewAndroid::DidCreateNewRendererCompositorFrameSink(
   surface_returned_resources_.clear();
 }
 
+void RenderWidgetHostViewAndroid::UpdateFullscreenStateAndEvictFrameIfNeeded() {
+  UpdateFullscreenState();
+  if (IsInFullscreenTransition()) {
+    // When we're in a fullscreen transition, we don't want to show a frame
+    // since it will look janky, so instead we show black.
+    EvictDelegatedFrame();
+    UpdateBackgroundColor(SK_ColorBLACK);
+    ClearThumbnailPlaceholder();
+  }
+}
+
+void RenderWidgetHostViewAndroid::UpdateFullscreenState() {
+  bool mismatched_fullscreen_states =
+      web_contents_is_fullscreen_ != current_frame_is_fullscreen_;
+  bool mismatched_sizes =
+      view_.GetPhysicalBackingSize() != current_surface_size_;
+
+  switch (fullscreen_state_) {
+    // From kNotFullscreen, we transition to kEnteringFullscreen whenever the
+    // fullscreen state changes.
+    case FullscreenState::kNotFullscreen:
+      if (mismatched_fullscreen_states) {
+        DCHECK(web_contents_is_fullscreen_);
+        fullscreen_state_ = FullscreenState::kEnteringFullscreen;
+        fullscreen_transition_awaiting_resize_ = true;
+      }
+      break;
+    // From kFullscreen, we transition to kExitingFullscreen on a fullscreen
+    // state change, or to kFullscreenRotation if we get a new size.
+    case FullscreenState::kFullscreen:
+      if (mismatched_fullscreen_states) {
+        DCHECK(!web_contents_is_fullscreen_);
+        fullscreen_state_ = FullscreenState::kExitingFullscreen;
+        fullscreen_transition_awaiting_resize_ = true;
+      } else if (mismatched_sizes) {
+        fullscreen_state_ = FullscreenState::kFullscreenRotation;
+      }
+      break;
+    // From any transition state, once we receive a "good" frame we transition
+    // to the proper "good" state.
+    case FullscreenState::kExitingFullscreen:
+    case FullscreenState::kEnteringFullscreen:
+    case FullscreenState::kFullscreenRotation:
+      if (!mismatched_fullscreen_states && !mismatched_sizes &&
+          !fullscreen_transition_awaiting_resize_) {
+        fullscreen_state_ = web_contents_is_fullscreen_
+                                ? FullscreenState::kFullscreen
+                                : FullscreenState::kNotFullscreen;
+      }
+      break;
+  }
+}
+
+bool RenderWidgetHostViewAndroid::IsInFullscreenTransition() const {
+  return (fullscreen_state_ == FullscreenState::kEnteringFullscreen ||
+          fullscreen_state_ == FullscreenState::kExitingFullscreen ||
+          fullscreen_state_ == FullscreenState::kFullscreenRotation);
+}
+
 void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
     const cc::LocalSurfaceId& local_surface_id,
     cc::CompositorFrame frame) {
@@ -1243,6 +1308,7 @@ void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
 
   frame_evictor_->DiscardedFrame();
   delegated_frame_host_->DestroyDelegatedContent();
+  current_surface_size_.SetSize(0, 0);
 }
 
 void RenderWidgetHostViewAndroid::OnDidNotProduceFrame(
@@ -1455,6 +1521,7 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
     touch_selection_controller_->OnViewportChanged(viewport_rect);
   }
 
+  current_frame_is_fullscreen_ = frame_metadata.is_fullscreen;
   UpdateBackgroundColor(is_transparent ? SK_ColorTRANSPARENT
                                        : frame_metadata.root_background_color);
 
@@ -1488,6 +1555,8 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
       frame_metadata.top_controls_height *
           frame_metadata.top_controls_shown_ratio,
       top_shown_pix, top_changed, is_mobile_optimized);
+
+  UpdateFullscreenStateAndEvictFrameIfNeeded();
 }
 
 void RenderWidgetHostViewAndroid::ShowInternal() {
@@ -1930,6 +1999,10 @@ SkColor RenderWidgetHostViewAndroid::GetCachedBackgroundColor() const {
   return cached_background_color_;
 }
 
+void RenderWidgetHostViewAndroid::ClearThumbnailPlaceholder() {
+  view_.ClearThumbnailPlaceholder();
+}
+
 void RenderWidgetHostViewAndroid::SetIsInVR(bool is_in_vr) {
   is_in_vr_ = is_in_vr;
 }
@@ -2059,6 +2132,8 @@ void RenderWidgetHostViewAndroid::OnGestureEvent(
 }
 
 void RenderWidgetHostViewAndroid::OnPhysicalBackingSizeChanged() {
+  fullscreen_transition_awaiting_resize_ = false;
+  UpdateFullscreenStateAndEvictFrameIfNeeded();
   WasResized();
 }