Fix compositor view caching logic

chrome/browser/android/compositor/compositor_view.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/compositor/compositor_view.h"
 
 #include <vector>
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
@@ skipping 196 matching lines @@
   compositor_->SetHasTransparentBackground(enabled);
   SetNeedsComposite(env, object);
 }
 
 void CompositorView::SetSceneLayer(JNIEnv* env,
                                    const JavaParamRef<jobject>& object,
                                    const JavaParamRef<jobject>& jscene_layer) {
   SceneLayer* scene_layer = SceneLayer::FromJavaObject(env, jscene_layer);
 
   if (scene_layer_ != scene_layer) {
-    // Old tree provider is being detached.
-    if (scene_layer_ != nullptr)
+    // The old tree should be detached only if it is not the cached layer or
+    // the cached layer is not somewhere in the new root.
+    if (scene_layer_ != nullptr
+        && !scene_layer_->layer()->HasAncestor(scene_layer->layer().get())) {
       scene_layer_->OnDetach();
+    }
 
     scene_layer_ = scene_layer;
 
     if (scene_layer == nullptr) {
       scene_layer_layer_ = nullptr;
       return;
     }
 
     scene_layer_layer_ = scene_layer->layer();
     root_layer_->InsertChild(scene_layer->layer(), 0);
@@ skipping 88 matching lines @@
   // through here but through BrowserChildProcessHostDisconnected() instead.
 }
 
 // Register native methods
 bool RegisterCompositorView(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace chrome