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 77970a3248eaf2d7971404ca46eaa89d33315b06..7880afe1b4fe5254f03243a0ead129c7cc4ee755 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -72,6 +72,7 @@
 #include "content/public/browser/devtools_agent_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_iterator.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
@@ -469,6 +470,7 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
       observing_root_window_(false),
       prev_top_shown_pix_(0.f),
       prev_bottom_shown_pix_(0.f),
+      fullscreen_jank_detector_(new FullscreenJankDetector()),
       mouse_wheel_phase_handler_(widget_host, this),
       weak_ptr_factory_(this) {
   // Set the layer which will hold the content layer for this view. The content
@@ -569,6 +571,12 @@ void RenderWidgetHostViewAndroid::WasResized() {
   host_->WasResized();
 }
 
+void RenderWidgetHostViewAndroid::OnFullscreenStateChanged() {
+  fullscreen_jank_detector_->OnFullscreenStateChanged(
+      host_->delegate()->IsFullscreenForCurrentTab());
+  EvictFrameIfNecessary();
+}
+
 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.
@@ -1195,6 +1203,19 @@ void RenderWidgetHostViewAndroid::DidCreateNewRendererCompositorFrameSink(
   surface_returned_resources_.clear();
 }
 
+void RenderWidgetHostViewAndroid::EvictFrameIfNecessary() {
+  // TODO(steimel): Remove this feature flag once we're confident that the
+  // fullscreen transition hiding is working correctly.

[mlamouri (slow - plz ping), 2017/07/05 13:55:31]

I would rephrase the TODO to say that we should remove the flag when the feature
has launched and is stable.

+  if (base::FeatureList::IsEnabled(features::kHideFullscreenTransitionJank) &&
+      fullscreen_jank_detector_->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::SubmitCompositorFrame(
     const cc::LocalSurfaceId& local_surface_id,
     cc::CompositorFrame frame) {
@@ -1254,6 +1275,7 @@ void RenderWidgetHostViewAndroid::DestroyDelegatedContent() {
 
   frame_evictor_->DiscardedFrame();
   delegated_frame_host_->DestroyDelegatedContent();
+  current_surface_size_.SetSize(0, 0);
 }
 
 void RenderWidgetHostViewAndroid::OnDidNotProduceFrame(
@@ -1497,6 +1519,10 @@ void RenderWidgetHostViewAndroid::OnFrameMetadataUpdated(
                      frame_metadata.max_page_scale_factor),
       frame_metadata.root_layer_size, frame_metadata.scrollable_viewport_size,
       top_content_offset, top_shown_pix, top_changed, is_mobile_optimized);
+
+  fullscreen_jank_detector_->OnFrameMetadataUpdated(
+      frame_metadata.is_fullscreen, current_surface_size_);
+  EvictFrameIfNecessary();
 }
 
 void RenderWidgetHostViewAndroid::ShowInternal() {
@@ -1979,6 +2005,10 @@ 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;
 }
@@ -2108,6 +2138,9 @@ void RenderWidgetHostViewAndroid::OnGestureEvent(
 }
 
 void RenderWidgetHostViewAndroid::OnPhysicalBackingSizeChanged() {
+  fullscreen_jank_detector_->OnPhysicalBackingSizeChanged(
+      view_.GetPhysicalBackingSize());
+  EvictFrameIfNecessary();
   WasResized();
 }