ash: ozone: apply transformation to events outside the root window

ash/host/ash_window_tree_host_ozone.cc

Index: ash/host/ash_window_tree_host_ozone.cc
diff --git a/ash/host/ash_window_tree_host_ozone.cc b/ash/host/ash_window_tree_host_ozone.cc
index 764eededa4163e8959b9ebf8cee8fbc8cf93111d..6dc42a79313b69f1f54810df4c3940d791d060f4 100644
--- a/ash/host/ash_window_tree_host_ozone.cc
+++ b/ash/host/ash_window_tree_host_ozone.cc
@@ -8,6 +8,7 @@
 #include "ash/host/root_window_transformer.h"
 #include "ash/host/transformer_helper.h"
 #include "base/command_line.h"
+#include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/window_tree_host_ozone.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/transform.h"
@@ -34,6 +35,9 @@ class AshWindowTreeHostOzone : public AshWindowTreeHost,
   virtual gfx::Transform GetRootTransform() const override;
   virtual gfx::Transform GetInverseRootTransform() const override;
   virtual void UpdateRootWindowSize(const gfx::Size& host_size) override;
+  virtual void DispatchEvent(ui::Event* event) override;
+
+  void TranslateMouseEvent(ui::LocatedEvent* event);
 
   TransformerHelper transformer_helper_;
 
@@ -87,6 +91,34 @@ void AshWindowTreeHostOzone::UpdateRootWindowSize(const gfx::Size& host_size) {
   transformer_helper_.UpdateWindowSize(host_size);
 }
 
+void AshWindowTreeHostOzone::DispatchEvent(ui::Event* event) {
+  if (event->IsMouseEvent() || event->IsScrollEvent())
+    TranslateMouseEvent(static_cast<ui::LocatedEvent*>(event));
+  SendEventToProcessor(event);
+}
+
+void AshWindowTreeHostOzone::TranslateMouseEvent(ui::LocatedEvent* event) {
+  aura::Window* root_window = window();
+  aura::client::ScreenPositionClient* screen_position_client =
+      aura::client::GetScreenPositionClient(root_window);
+  gfx::Rect local(GetBounds().size());
+
+  local.Inset(transformer_helper_.GetHostInsets());
+
+  if (screen_position_client && !local.Contains(event->location())) {
+    gfx::Point location(event->location());
+    // In order to get the correct point in screen coordinates during
+    // passive grab, we first need to find on which host window the
+    // mouse is on, and find out the screen coordinates on that host
+    // window, then convert it back to this host window's coordinate.
+    screen_position_client->ConvertHostPointToScreen(root_window, &location);
+    screen_position_client->ConvertPointFromScreen(root_window, &location);
+    ConvertPointToHost(&location);
+    event->set_location(location);
+    event->set_root_location(location);
+  }
+}
+
 }  // namespace
 
 AshWindowTreeHost* AshWindowTreeHost::Create(