Do not lose secondary gpus and make sure to have an active gpu on multiple gpu configurations

content/public/common/content_switches.cc

 // Copyright (c) 2012 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 "build/build_config.h"
 #include "content/public/common/content_switches.h"
 
 namespace switches {
 
 // The number of MSAA samples for canvas2D. Requires MSAA support by GPU to
@@ skipping 543 matching lines @@
 
 // Starts the GPU sandbox before creating a GL context.
 const char kGpuSandboxStartEarly[]          = "gpu-sandbox-start-early";
 
 // Causes the GPU process to display a dialog on launch.
 const char kGpuStartupDialog[]              = "gpu-startup-dialog";
 
 // Passes gpu vendor_id from browser process to GPU process.
 const char kGpuVendorID[]                   = "gpu-vendor-id";
 
+// Passes secondary gpu vendor ids from browser process to GPU process.
+const char kGpuSecondaryVendorIDs[] = "gpu-secondary-vendor-ids";
+
+// Passes secondary gpu device ids from browser process to GPU process.
+const char kGpuSecondaryDeviceIDs[] = "gpu-secondary-device-ids";
+
 // These mappings only apply to the host resolver.
 const char kHostResolverRules[]             = "host-resolver-rules";
 
 // Ignores certificate-related errors.
 const char kIgnoreCertificateErrors[]       = "ignore-certificate-errors";
 
 // Ignores GPU blacklist.
 const char kIgnoreGpuBlacklist[]            = "ignore-gpu-blacklist";
 
 // Makes all APIs reflect the layout viewport.
@@ skipping 447 matching lines @@
 const char kMemoryPressureThresholdsMb[] = "memory-pressure-thresholds-mb";
 
 // Enables the exporting of the tracing events to ETW. This is only supported on
 // Windows Vista and later.
 const char kTraceExportEventsToETW[] = "trace-export-events-to-etw";
 #endif
 
 // Don't dump stuff here, follow the same order as the header.
 
 }  // namespace switches