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..e20938dc69459780d9375cbbd0b88f20bf4a7b55 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;
+  EvictFrameIfNecessary(false);

[Khushal, 2017/06/14 19:43:14]

nit: UpdateFullscreenState?

[steimel, 2017/06/14 21:46:16]

Done.

+}
+
 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 +1190,62 @@ void RenderWidgetHostViewAndroid::DidCreateNewRendererCompositorFrameSink(
   surface_returned_resources_.clear();
 }
 
+void RenderWidgetHostViewAndroid::EvictFrameIfNecessary(
+    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) {

[liberato (no reviews please), 2017/06/14 21:01:50]

nit: no need for {}

[steimel, 2017/06/14 21:46:16]

Done.

+    awaiting_resize_ = false;
+  }
+
+  switch (fullscreen_state_) {
+    // From kNotFullscreen, we transition to kEnteringFullscreen whenever the
+    // fullscreen state changes.
+    case FullscreenState::kNotFullscreen:
+      if (mismatched_fullscreen_states) {

[Khushal, 2017/06/14 19:43:14]

Should this be a DCHECK that web_contents_is_fullscreen_? Because the renderer
doesn't transition until the browser Acks the request.

[steimel, 2017/06/14 21:46:16]

Done.

+        fullscreen_state_ = FullscreenState::kEnteringFullscreen;
+        awaiting_resize_ = !physical_backing_resized;

[Khushal, 2017/06/14 19:43:14]

This should also be a DCHECK I think. You should definitely see a resize *after*
the transition is requested.

[steimel, 2017/06/14 21:46:16]

Done.

+      }
+      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) {

[Khushal, 2017/06/14 19:43:14]

Same DCHECKs here but flipped. Browser transitions out of fullscreen first and
you should see a resize for sure.

[steimel, 2017/06/14 21:46:16]

Done.

+        fullscreen_state_ = FullscreenState::kExitingFullscreen;
+        awaiting_resize_ = !physical_backing_resized;
+      }
+      if (mismatched_sizes) {
+        // TODO(steimel): Do we want to restrict this transition to when the
+        // width/height have swapped (indicating a proper rotation), or are we
+        // fine with any size change being treated as a rotation?
+        fullscreen_state_ = FullscreenState::kFullscreenRotation;

[Khushal, 2017/06/14 19:43:14]

The only reason we needed the extra state was to use in CanShowThumbnail right?
I'd prefer just evicting the frame on any size mismatch while in fullscreen and
not showing the thumbnail at all in fullscreen state. But this is good too.

[steimel, 2017/06/14 21:46:16]

Acknowledged.

+      }
+      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 &&
+          !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 +1259,7 @@ 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 +1291,8 @@ 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);
+
+  EvictFrameIfNecessary(false);
 }
 
 void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
@@ -1243,6 +1308,7 @@ void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
 
   frame_evictor_->DiscardedFrame();
   delegated_frame_host_->DestroyDelegatedContent();
+  current_surface_size_.SetSize(0, 0);
 }
 
 void RenderWidgetHostViewAndroid::OnDidNotProduceFrame(
@@ -2059,6 +2125,9 @@ void RenderWidgetHostViewAndroid::OnGestureEvent(
 }
 
 void RenderWidgetHostViewAndroid::OnPhysicalBackingSizeChanged() {
+  // If we're entering a fullscreen transition, show black until the transition
+  // is completed.
+  EvictFrameIfNecessary(true);
   WasResized();
 }