Bug 1600652 - Update Scroll frame metrics for android so text select popup is in correct location. r=botond

Differential Revision: https://phabricator.services.mozilla.com/D58165

--HG--
extra : moz-landing-system : lando

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -731,6 +731,16 @@ void APZCTreeManager::SampleForWebRender(wr::TransactionWrapper& aTxn,
                               wr::ToLayoutPoint(asyncScrollDelta));
 
     apzc->ReportCheckerboard(aSampleTime);
+
+#if defined(MOZ_WIDGET_ANDROID)
+    // Send the root frame metrics to java through the UIController
+    RefPtr<UiCompositorControllerParent> uiController =
+        UiCompositorControllerParent::GetFromRootLayerTreeId(mRootLayersId);
+    if (uiController &&
+        apzc->UpdateRootFrameMetricsIfChanged(mLastRootMetrics)) {
+      uiController->NotifyUpdateScreenMetrics(mLastRootMetrics);
+    }
+#endif
   }
 
   // Now collect all the async transforms needed for the scrollthumbs.

gfx/layers/apz/src/APZCTreeManager.h

@@ -954,6 +954,9 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
 
  private:
   RefPtr<AndroidDynamicToolbarAnimator> mToolbarAnimator;
+
+  // Last Frame metrics sent to java through UIController.
+  FrameMetrics mLastRootMetrics;
 #endif  // defined(MOZ_WIDGET_ANDROID)
 };
 

gfx/layers/apz/src/AsyncPanZoomController.cpp

@@ -4800,6 +4800,24 @@ const FrameMetrics& AsyncPanZoomController::Metrics() const {
   ;
 }
 
+bool AsyncPanZoomController::UpdateRootFrameMetricsIfChanged(
+    FrameMetrics& metrics) {
+  RecursiveMutexAutoLock lock(mRecursiveMutex);
+
+  const FrameMetrics& aMetrics = Metrics();
+  if (!aMetrics.IsRootContent()) return false;
+
+  bool hasChanged = RoundedToInt(metrics.GetScrollOffset()) !=
+                        RoundedToInt(aMetrics.GetScrollOffset()) ||
+                    metrics.GetZoom() != aMetrics.GetZoom();
+
+  if (hasChanged) {
+    metrics = aMetrics;
+  }
+
+  return hasChanged;
+}
+
 const FrameMetrics& AsyncPanZoomController::GetFrameMetrics() const {
   return Metrics();
 }

gfx/layers/apz/src/AsyncPanZoomController.h

@@ -554,6 +554,10 @@ class AsyncPanZoomController {
   const FrameMetrics& Metrics() const;
   FrameMetrics& Metrics();
 
+  // Helper function to compare root frame metrics and update them
+  // Returns true when the metrics have changed and were updated.
+  bool UpdateRootFrameMetricsIfChanged(FrameMetrics& metrics);
+
  private:
   // Get whether the horizontal content of the honoured target of auto-dir
   // scrolling starts from right to left. If you don't know of auto-dir