Fix bug whereby OnGpuSwitched was never called

gpu/config/gpu_info.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 <stdint.h>
 
 #include "gpu/config/gpu_info.h"
 
 namespace {
 
@@ skipping 75 matching lines @@
       system_visual(0),
       rgba_visual(0)
 #endif
 {
 }
 
 GPUInfo::GPUInfo(const GPUInfo& other) = default;
 
 GPUInfo::~GPUInfo() { }
 
+const GPUInfo::GPUDevice& GPUInfo::active_gpu() const {
+  if (gpu.active)
+    return gpu;
+  for (const GPUDevice& secondary_gpu : secondary_gpus) {
+    if (secondary_gpu.active)
+      return secondary_gpu;
+  }
+  DLOG(ERROR) << "No active GPU found, returning primary GPU.";
+  return gpu;
+}
+
 void GPUInfo::EnumerateFields(Enumerator* enumerator) const {
   struct GPUInfoKnownFields {
     base::TimeDelta initialization_time;
     bool optimus;
     bool amd_switchable;
     GPUDevice gpu;
     std::vector<GPUDevice> secondary_gpus;
     std::string driver_vendor;
     std::string driver_version;
     std::string driver_date;
@@ skipping 92 matching lines @@
   enumerator->AddBool("jpegDecodeAcceleratorSupported",
       jpeg_decode_accelerator_supported);
 #if defined(USE_X11) && !defined(OS_CHROMEOS)
   enumerator->AddInt64("systemVisual", system_visual);
   enumerator->AddInt64("rgbaVisual", rgba_visual);
 #endif
   enumerator->EndAuxAttributes();
 }
 
 }  // namespace gpu