[2/2][Ozone-Drm] Scan for displays on browser size during startup

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

Index: ui/ozone/platform/drm/host/drm_display_host_manager.cc
diff --git a/ui/ozone/platform/drm/host/drm_display_host_manager.cc b/ui/ozone/platform/drm/host/drm_display_host_manager.cc
index 93d43e2467de430ae2cec6ce1655f6eb33dd403d..2feb1f4bae102cf2ac87b537968f936f19efce58 100644
--- a/ui/ozone/platform/drm/host/drm_display_host_manager.cc
+++ b/ui/ozone/platform/drm/host/drm_display_host_manager.cc
@@ -13,12 +13,12 @@
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/threading/worker_pool.h"
-#include "ui/display/types/display_snapshot.h"
 #include "ui/events/ozone/device/device_event.h"
 #include "ui/events/ozone/device/device_manager.h"
 #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/drm/common/drm_util.h"
 #include "ui/ozone/platform/drm/host/drm_device_handle.h"
 #include "ui/ozone/platform/drm/host/drm_gpu_platform_support_host.h"
 #include "ui/ozone/platform/drm/host/drm_native_display_delegate.h"
@@ -122,27 +122,13 @@ DrmDisplayHostManager::DrmDisplayHostManager(DrmGpuPlatformSupportHost* proxy,
   device_manager_->AddObserver(this);
   proxy_->RegisterHandler(this);
 
-  DisplaySnapshot_Params params;
-  bool success = false;
-  {
-    // The file generated by frecon that contains EDID for the 1st display.
-    const base::FilePath kEDIDFile("/tmp/display_info.bin");
-
-    // Just read it on current thread as this is necessary information
-    // to start. This access only tmpfs, which is fast.
-    // TODO(dnicoara|oshima): crbug.com/450886.
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
-    success = CreateSnapshotFromEDIDFile(kEDIDFile, &params);
-  }
-
-  // Fallback to command line if the file doesn't exit or failed to read.
-  if (success || CreateSnapshotFromCommandLine(&params)) {
-    LOG_IF(ERROR, !success) << "Failed to read display_info.bin.";
-    DCHECK_NE(DISPLAY_CONNECTION_TYPE_NONE, params.type);
-    displays_.push_back(new DisplaySnapshotProxy(params));
-    has_dummy_display_ = true;
-  } else {
-    LOG(ERROR) << "Failed to obtain initial display info";
+  DrmDeviceHandle* handle = drm_devices_.get(primary_graphics_card_path_);
+  ScopedVector<HardwareDisplayControllerInfo> display_infos =
+      GetAvailableDisplayControllerInfos(handle->fd());
+  has_dummy_display_ = !display_infos.empty();
+  for (size_t i = 0; i < display_infos.size(); ++i) {
+    displays_.push_back(new DisplaySnapshotProxy(CreateDisplaySnapshotParams(
+        display_infos[i], handle->fd(), i, gfx::Point())));
   }
 }