exo: Fix sub surface input event support.

components/exo/surface.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 "components/exo/surface.h"
 
 #include <utility>
 
 #include "base/callback_helpers.h"
 #include "base/logging.h"
@@ skipping 52 matching lines @@
                        const gfx::Rect& new_bounds) override {}
   gfx::NativeCursor GetCursor(const gfx::Point& point) override {
     return gfx::kNullCursor;
   }
   int GetNonClientComponent(const gfx::Point& point) const override {
     return HTNOWHERE;
   }
   bool ShouldDescendIntoChildForEventHandling(
       aura::Window* child,
       const gfx::Point& location) override {
-    return false;
+    return true;
   }
   bool CanFocus() override { return true; }
   void OnCaptureLost() override {}
   void OnPaint(const ui::PaintContext& context) override {}
   void OnDeviceScaleFactorChanged(float device_scale_factor) override {}
   void OnWindowDestroying(aura::Window* window) override {}
   void OnWindowDestroyed(aura::Window* window) override { delete this; }
   void OnWindowTargetVisibilityChanged(bool visible) override {}
   bool HasHitTestMask() const override { return false; }
   void GetHitTestMask(gfx::Path* mask) const override {}
@@ skipping 344 matching lines @@
   // of the surface next time the compositor successfully ends compositing.
   update_contents_after_successful_compositing_ = true;
 }
 
 void Surface::OnCompositingShuttingDown(ui::Compositor* compositor) {
   compositor->RemoveObserver(this);
   compositor_ = nullptr;
 }
 
 }  // namespace exo