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..bee437476aed0f800e82ac9d464350a80bc58c63 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;
+  UpdateFullscreenState(false);
+}
+
 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 +1190,61 @@ void RenderWidgetHostViewAndroid::DidCreateNewRendererCompositorFrameSink(
   surface_returned_resources_.clear();
 }
 
+void RenderWidgetHostViewAndroid::UpdateFullscreenState(
+    bool physical_backing_resized) {
+  bool mismatched_fullscreen_states =
+      web_contents_is_fullscreen_ != current_frame_is_fullscreen_;
+  bool mismatched_sizes =
+      view_.GetPhysicalBackingSize() != current_surface_size_;
+
+  if (physical_backing_resized)
+    fullscreen_transition_awaiting_resize_ = false;
+
+  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_);
+        DCHECK(!physical_backing_resized);
+        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_);
+        DCHECK(!physical_backing_resized);
+        fullscreen_state_ = FullscreenState::kExitingFullscreen;
+        fullscreen_transition_awaiting_resize_ = true;
+      }
+      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:

[Khushal, 2017/06/15 18:42:55]

nit: Would it be better if we handled the 3 transitions here separately. So
kEntering goes to kFullscreen and kExiting goes to kNotFullscreen? And you can
DCHECK on the |web_content_is_fullscreen_| to see that its expected.

[steimel, 2017/06/15 21:46:38]

Discussed offline. Holding off on updating the transition logic for now

+    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;
+  }
+
+  if (fullscreen_state_ == FullscreenState::kEnteringFullscreen ||
+      fullscreen_state_ == FullscreenState::kExitingFullscreen ||
+      fullscreen_state_ == FullscreenState::kFullscreenRotation) {
+    EvictDelegatedFrame();
+    UpdateBackgroundColor(SK_ColorBLACK);
+  }
+}
+
 void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
     const cc::LocalSurfaceId& local_surface_id,
     cc::CompositorFrame frame) {
@@ -1197,6 +1258,7 @@ void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
 
   cc::RenderPass* root_pass = frame.render_pass_list.back().get();
   current_surface_size_ = root_pass->output_rect.size();
+  current_frame_is_fullscreen_ = frame.metadata.is_fullscreen;
   bool is_transparent = root_pass->has_transparent_background;
 
   cc::CompositorFrameMetadata metadata = frame.metadata.Clone();
@@ -1228,6 +1290,8 @@ void RenderWidgetHostViewAndroid::SubmitCompositorFrame(
   // As the metadata update may trigger view invalidation, always call it after
   // any potential compositor scheduling.
   OnFrameMetadataUpdated(std::move(metadata), is_transparent);
+
+  UpdateFullscreenState(false);
 }
 
 void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
@@ -1243,6 +1307,7 @@ void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
 
   frame_evictor_->DiscardedFrame();
   delegated_frame_host_->DestroyDelegatedContent();
+  current_surface_size_.SetSize(0, 0);
 }
 
 void RenderWidgetHostViewAndroid::OnDidNotProduceFrame(
@@ -1930,6 +1995,12 @@ SkColor RenderWidgetHostViewAndroid::GetCachedBackgroundColor() const {
   return cached_background_color_;
 }
 
+bool RenderWidgetHostViewAndroid::CanShowThumbnailPlaceholder() const {
+  return !(fullscreen_state_ == FullscreenState::kEnteringFullscreen ||
+           fullscreen_state_ == FullscreenState::kExitingFullscreen ||
+           fullscreen_state_ == FullscreenState::kFullscreenRotation);
+}
+
 void RenderWidgetHostViewAndroid::SetIsInVR(bool is_in_vr) {
   is_in_vr_ = is_in_vr;
 }
@@ -2059,6 +2130,9 @@ void RenderWidgetHostViewAndroid::OnGestureEvent(
 }
 
 void RenderWidgetHostViewAndroid::OnPhysicalBackingSizeChanged() {
+  // If we're entering a fullscreen transition, show black until the transition
+  // is completed.
+  UpdateFullscreenState(true);
   WasResized();
 }