[ozone/wayland]: Improve DataDevice initialization

This CL is intended to make the Wayland data device
initialization more robust, removing the assumption
that data device manager global object is advertised
before the wl_seat.

Additionally this patch does a minor code cleanup in
WaylandDataDeviceManager, removing the WaylandConnection
setter, injecting connection instance via its constructor
instead, as it is already being done in other classes, such
as WaylandDataSource, for example.

Bug: 578890
Change-Id: Ia700c164f18b2778b08047bfcb5ccf382e69328f
Reviewed-on: https://chromium-review.googlesource.com/c/1487853Reviewed-by: Maksim Sisov <msisov@igalia.com>
Reviewed-by: Antonio Gomes <tonikitoo@igalia.com>
Commit-Queue: Nick Diego Yamane <nickdiego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#635489}

ui/ozone/platform/wayland/wayland_connection.cc

@@ -405,6 +405,14 @@ void WaylandConnection::TerminateGpuProcess(std::string reason) {
   buffer_manager_->ClearState();
 }
 
+void WaylandConnection::EnsureDataDevice() {
+  if (!data_device_manager_ || !seat_)
+    return;
+  DCHECK(!data_device_);
+  wl_data_device* data_device = data_device_manager_->GetDevice();
+  data_device_ = std::make_unique<WaylandDataDevice>(this, data_device);
+}
+
 // static
 void WaylandConnection::Global(void* data,
                                wl_registry* registry,
@@ -448,19 +456,7 @@ void WaylandConnection::Global(void* data,
       return;
     }
     wl_seat_add_listener(connection->seat_.get(), &seat_listener, connection);
-
-    // TODO(tonikitoo,msisov): The connection passed to WaylandInputDevice must
-    // have a valid data device manager. We should ideally be robust to the
-    // compositor advertising a wl_seat first. No known compositor does this,
-    // fortunately.
-    if (!connection->data_device_manager_) {
-      LOG(ERROR)
-          << "No data device manager. Clipboard won't be fully functional";
-      return;
-    }
-    wl_data_device* data_device = connection->data_device_manager_->GetDevice();
-    connection->data_device_.reset(
-        new WaylandDataDevice(connection, data_device));
+    connection->EnsureDataDevice();
   } else if (!connection->shell_v6_ &&
              strcmp(interface, "zxdg_shell_v6") == 0) {
     // Check for zxdg_shell_v6 first.
@@ -514,9 +510,9 @@ void WaylandConnection::Global(void* data,
       LOG(ERROR) << "Failed to bind to wl_data_device_manager global";
       return;
     }
-    connection->data_device_manager_.reset(
-        new WaylandDataDeviceManager(data_device_manager.release()));
-    connection->data_device_manager_->set_connection(connection);
+    connection->data_device_manager_.reset(new WaylandDataDeviceManager(
+        data_device_manager.release(), connection));
+    connection->EnsureDataDevice();
   } else if (!connection->buffer_manager_ &&
              (strcmp(interface, "zwp_linux_dmabuf_v1") == 0)) {
     wl::Object<zwp_linux_dmabuf_v1> zwp_linux_dmabuf =

ui/ozone/platform/wayland/wayland_connection.h

@@ -199,6 +199,9 @@ class WaylandConnection : public PlatformEventSource,
   // Terminates the GPU process on invalid data received
   void TerminateGpuProcess(std::string reason);
 
+  // Make sure data device is properly initialized
+  void EnsureDataDevice();
+
   // wl_registry_listener
   static void Global(void* data,
                      wl_registry* registry,

ui/ozone/platform/wayland/wayland_data_device_manager.cc

@@ -9,8 +9,12 @@
 namespace ui {
 
 WaylandDataDeviceManager::WaylandDataDeviceManager(
-    wl_data_device_manager* device_manager)
-    : device_manager_(device_manager) {}
+    wl_data_device_manager* device_manager,
+    WaylandConnection* connection)
+    : device_manager_(device_manager), connection_(connection) {
+  DCHECK(connection_);
+  DCHECK(device_manager_);
+}
 
 WaylandDataDeviceManager::~WaylandDataDeviceManager() = default;
 

ui/ozone/platform/wayland/wayland_data_device_manager.h

@@ -7,7 +7,6 @@
 
 #include <wayland-client.h>
 
-#include "base/logging.h"
 #include "base/macros.h"
 #include "ui/ozone/platform/wayland/wayland_object.h"
 
@@ -17,21 +16,17 @@ class WaylandConnection;
 
 class WaylandDataDeviceManager {
  public:
-  explicit WaylandDataDeviceManager(wl_data_device_manager* device_manager);
+  WaylandDataDeviceManager(wl_data_device_manager* device_manager,
+                           WaylandConnection* connection);
   ~WaylandDataDeviceManager();
 
   wl_data_device* GetDevice();
   wl_data_source* CreateSource();
 
-  void set_connection(WaylandConnection* connection) {
-    DCHECK(connection);
-    connection_ = connection;
-  }
-
  private:
   wl::Object<wl_data_device_manager> device_manager_;
 
-  WaylandConnection* connection_ = nullptr;
+  WaylandConnection* connection_;
 
   DISALLOW_COPY_AND_ASSIGN(WaylandDataDeviceManager);
 };