From 269f751ce7e71e1f3aea62d604b17557ae3b727c Mon Sep 17 00:00:00 2001
From: James Willcox <snorp@snorp.net>
Date: Thu, 17 Jan 2019 14:17:50 +0000
Subject: [PATCH] Bug 1514253 - Create PanZoomController immediately in
 GeckoSession r=geckoview-reviewers,droeh#geckoview-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D14562

--HG--
extra : moz-landing-system : lando
---
 .../java/org/mozilla/geckoview/GeckoSession.java  | 15 +++------------
 widget/android/nsWindow.cpp                       |  9 ++++++++-
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java
index 05f1040e0c07..950cfa0fc15b 100644
--- a/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoSession.java
@@ -107,7 +107,7 @@ public class GeckoSession implements Parcelable {
     private boolean mShouldPinOnScreen;
 
     // All fields are accessed on UI thread only.
-    private PanZoomController mNPZC;
+    private PanZoomController mPanZoomController = new PanZoomController(this);
     private OverscrollEdgeEffect mOverscroll;
     private DynamicToolbarAnimator mToolbar;
     private CompositorController mController;
@@ -3658,13 +3658,7 @@ public class GeckoSession implements Parcelable {
     public @NonNull PanZoomController getPanZoomController() {
         ThreadUtils.assertOnUiThread();
 
-        if (mNPZC == null) {
-            mNPZC = new PanZoomController(this);
-            if (mAttachedCompositor) {
-                mCompositor.attachNPZC(mNPZC);
-            }
-        }
-        return mNPZC;
+        return mPanZoomController;
     }
 
     /**
@@ -4340,10 +4334,7 @@ public class GeckoSession implements Parcelable {
         }
 
         mAttachedCompositor = true;
-
-        if (mNPZC != null) {
-            mCompositor.attachNPZC(mNPZC);
-        }
+        mCompositor.attachNPZC(mPanZoomController);
 
         if (mSurface != null) {
             // If we have a valid surface, create the compositor now that we're attached.
diff --git a/widget/android/nsWindow.cpp b/widget/android/nsWindow.cpp
index a88e576fa4e8..e8f92242efa1 100644
--- a/widget/android/nsWindow.cpp
+++ b/widget/android/nsWindow.cpp
@@ -890,7 +890,14 @@ class nsWindow::LayerViewSupport final
     }
 
     MOZ_ASSERT(aNPZC);
-    MOZ_ASSERT(!mWindow->mNPZCSupport);
+
+    // We can have this situation if we get two GeckoViewSupport::Transfer()
+    // called before the first AttachNPZC() gets here. Just detach the current
+    // instance since that's what happens in GeckoViewSupport::Transfer() as
+    // well.
+    if (mWindow->mNPZCSupport) {
+      mWindow->mNPZCSupport.Detach(mWindow->mNPZCSupport->GetJavaNPZC());
+    }
 
     auto npzc = PanZoomController::LocalRef(
         jni::GetGeckoThreadEnv(), PanZoomController::Ref::From(aNPZC));