[WIP][Ozone] Support external touchscreens

ui/ozone/platform/dri/native_display_delegate_proxy.cc

Index: ui/ozone/platform/dri/native_display_delegate_proxy.cc
diff --git a/ui/ozone/platform/dri/native_display_delegate_proxy.cc b/ui/ozone/platform/dri/native_display_delegate_proxy.cc
index 95600d2464369a701c0cb3f92e6582e50c25f80d..f6e3fbda2d73eaf412bed78c9e560e8e7c3a1506 100644
--- a/ui/ozone/platform/dri/native_display_delegate_proxy.cc
+++ b/ui/ozone/platform/dri/native_display_delegate_proxy.cc
@@ -12,14 +12,40 @@
 #include "ui/ozone/common/display_snapshot_proxy.h"
 #include "ui/ozone/common/display_util.h"
 #include "ui/ozone/common/gpu/ozone_gpu_messages.h"
+#include "ui/ozone/platform/dri/display_manager.h"
 #include "ui/ozone/platform/dri/dri_gpu_platform_support_host.h"
 
 namespace ui {
 
+namespace {
+
+class DriDisplaySnapshotProxy : public DisplaySnapshotProxy {
+ public:
+  DriDisplaySnapshotProxy(const DisplaySnapshot_Params& params,
+                          DisplayManager* display_manager)
+      : DisplaySnapshotProxy(params), display_manager_(display_manager) {
+    display_manager_->RegisterDisplay(this);
+  }
+
+  virtual ~DriDisplaySnapshotProxy() {
+    display_manager_->UnregisterDisplay(this);
+  }
+
+ private:
+  DisplayManager* display_manager_;  // Not owned.
+
+  DISALLOW_COPY_AND_ASSIGN(DriDisplaySnapshotProxy);
+};
+
+}  // namespace
+
 NativeDisplayDelegateProxy::NativeDisplayDelegateProxy(
     DriGpuPlatformSupportHost* proxy,
-    DeviceManager* device_manager)
-    : proxy_(proxy), device_manager_(device_manager) {
+    DeviceManager* device_manager,
+    DisplayManager* display_manager)
+    : proxy_(proxy),
+      device_manager_(device_manager),
+      display_manager_(display_manager) {
   proxy_->RegisterHandler(this);
 }
 
@@ -153,7 +179,8 @@ void NativeDisplayDelegateProxy::OnUpdateNativeDisplays(
     const std::vector<DisplaySnapshot_Params>& displays) {
   displays_.clear();
   for (size_t i = 0; i < displays.size(); ++i)
-    displays_.push_back(new DisplaySnapshotProxy(displays[i]));
+    displays_.push_back(
+        new DriDisplaySnapshotProxy(displays[i], display_manager_));
 
   FOR_EACH_OBSERVER(
       NativeDisplayObserver, observers_, OnConfigurationChanged());