Hide fullscreen rotation jank

chrome/browser/android/compositor/compositor_view.cc

Index: chrome/browser/android/compositor/compositor_view.cc
diff --git a/chrome/browser/android/compositor/compositor_view.cc b/chrome/browser/android/compositor/compositor_view.cc
index 4b525711cbc5f59c6f6a1e0f101bafb52872234a..a2faa8e4c3ca4f17f51cb3662847be4bdd674d62 100644
--- a/chrome/browser/android/compositor/compositor_view.cc
+++ b/chrome/browser/android/compositor/compositor_view.cc
@@ -29,6 +29,7 @@
 #include "content/public/browser/android/content_view_core.h"
 #include "content/public/browser/child_process_data.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/process_type.h"
 #include "jni/CompositorView_jni.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ -185,10 +186,22 @@ void CompositorView::SetLayoutBounds(JNIEnv* env,
 }
 
 void CompositorView::SetBackground(bool visible, SkColor color) {
-  if (overlay_video_mode_)
+  // TODO(steimel): Remove this feature flag and the hack inside this if block
+  // once we're confident that the fullscreen transition hiding is working
+  // properly.
+  if (!base::FeatureList::IsEnabled(features::kHideFullscreenTransitionJank) &&
+      overlay_video_mode_) {
     visible = false;
+  }
   root_layer_->SetBackgroundColor(color);
   root_layer_->SetIsDrawable(visible);
+  // TODO(steimel): Remove this feature flag check once we're confident that the
+  // fullscreen transition hiding is working properly.
+  if (base::FeatureList::IsEnabled(features::kHideFullscreenTransitionJank)) {
+    compositor_->SetBackgroundColor(color);
+    compositor_->SetHasTransparentBackground(SkColorGetA(color) ==
+                                             SK_AlphaTRANSPARENT);
+  }
 }
 
 void CompositorView::SetOverlayVideoMode(JNIEnv* env,
@@ -197,7 +210,12 @@ void CompositorView::SetOverlayVideoMode(JNIEnv* env,
   if (overlay_video_mode_ == enabled)
     return;
   overlay_video_mode_ = enabled;
-  compositor_->SetHasTransparentBackground(enabled);
+  // TODO(steimel): Remove this feature flag and the hack inside this if block
+  // once we're confident that the fullscreen transition hiding is working
+  // properly.
+  if (!base::FeatureList::IsEnabled(features::kHideFullscreenTransitionJank)) {
+    compositor_->SetHasTransparentBackground(enabled);
+  }
   SetNeedsComposite(env, object);
 }