native_viewport support for ozone

ui/ozone/platform/drm/host/drm_display_host_manager.cc

 // Copyright 2014 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 "ui/ozone/platform/drm/host/drm_display_host_manager.h"
 
 #include <fcntl.h>
 #include <xf86drm.h>
 
 #include "base/files/file_enumerator.h"
@@ skipping 205 matching lines @@
 
   relinquish_display_control_callback_ = callback;
   display_control_change_pending_ = true;
 
   if (!proxy_->RelinquishDisplayControl())
     OnRelinquishDisplayControl(false);
 }
 
 void DrmDisplayHostManager::UpdateDisplays(
     const GetDisplaysCallback& callback) {
+  DCHECK(get_displays_callback_.is_null());
   get_displays_callback_ = callback;
   if (!proxy_->RefreshNativeDisplays()) {
     get_displays_callback_.Reset();
     RunUpdateDisplaysCallback(callback);
   }
 }
 
 void DrmDisplayHostManager::OnDeviceEvent(const DeviceEvent& event) {
   if (event.device_type() != DeviceEvent::DISPLAY)
     return;
@@ skipping 64 matching lines @@
   ProcessEvent();
 }
 
 void DrmDisplayHostManager::OnRemoveGraphicsDevice(const base::FilePath& path) {
   proxy_->RemoveGraphicsDevice(path);
   NotifyDisplayDelegate();
   task_pending_ = false;
   ProcessEvent();
 }
 
-void DrmDisplayHostManager::OnChannelEstablished(int host_id) {
-  // If in the middle of a configuration, just respond with the old list of
-  // displays. This is fine, since after the DRM resources are initialized and
-  // IPC-ed to the GPU NotifyDisplayDelegate() is called to let the display
-  // delegate know that the display configuration changed and it needs to
-  // update it again.
-  if (!get_displays_callback_.is_null()) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(&DrmDisplayHostManager::RunUpdateDisplaysCallback,
-                   weak_ptr_factory_.GetWeakPtr(), get_displays_callback_));
-    get_displays_callback_.Reset();
-  }
+void DrmDisplayHostManager::OnChannelEstablished() {
+  // If in the middle of a configuration - don't respond here.
+  // Chromium does so, but that causes a problem:
+  // NotifyDisplayDelegate, below, triggers a new update display request which
+  // is
+  // fulfilled by the results from the first request. That result is empty
+  // because
+  // we haven't added a drm device yet).
+  // The second update display request generates non empty results,
+  // but those won't be forwarded to the observer because there is no longer
+  // an outstanding request.
 
   // Signal that we're taking DRM master since we're going through the
   // initialization process again and we'll take all the available resources.
   if (!take_display_control_callback_.is_null())
     OnTakeDisplayControl(true);
 
   if (!relinquish_display_control_callback_.is_null())
     OnRelinquishDisplayControl(false);
 
   drm_devices_.clear();
   drm_devices_.insert(primary_graphics_card_path_);
   scoped_ptr<DrmDeviceHandle> handle = primary_drm_device_handle_.Pass();
   if (!handle) {
     handle.reset(new DrmDeviceHandle());
     if (!handle->Initialize(primary_graphics_card_path_))
       LOG(FATAL) << "Failed to open primary graphics card";
   }
 
   // Send the primary device first since this is used to initialize graphics
   // state.
   proxy_->AddGraphicsDevice(primary_graphics_card_path_,
                             base::FileDescriptor(handle->PassFD()));
 
   device_manager_->ScanDevices(this);
   NotifyDisplayDelegate();
 }
 
-void DrmDisplayHostManager::OnChannelDestroyed(int host_id) {
+void DrmDisplayHostManager::OnChannelDestroyed() {
   // Do nothing.
 }
 
 void DrmDisplayHostManager::OnUpdateNativeDisplays(
     const std::vector<DisplaySnapshot_Params>& params) {
   ScopedVector<DrmDisplayHost> old_displays(displays_.Pass());
   for (size_t i = 0; i < params.size(); ++i) {
     auto it = std::find_if(old_displays.begin(), old_displays.end(),
                            FindDrmDisplayHostById(params[i].display_id));
     if (it == old_displays.end()) {
@@ skipping 91 matching lines @@
 
   callback.Run(snapshots);
 }
 
 void DrmDisplayHostManager::NotifyDisplayDelegate() const {
   if (delegate_)
     delegate_->OnConfigurationChanged();
 }
 
 }  // namespace ui