Avoid GpuPreferences exposed in content public gpu interface

content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc

Index: content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
diff --git a/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc b/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
index c3cd7ee1e710b27e8f37e27b6a0043f45e34adb4..6822c7e230801acb716d9b172cc80c1e2155356c 100644
--- a/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
+++ b/content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.cc
@@ -5,6 +5,7 @@
 #include "content/common/gpu/media/gpu_video_accelerator_util.h"
 #include "content/common/gpu/media/gpu_video_decode_accelerator.h"
 #include "content/common/gpu/media/gpu_video_decode_accelerator_factory_impl.h"
+#include "content/gpu/gpu_child_thread.h"
 #include "gpu/command_buffer/service/gpu_preferences.h"
 
 #if defined(OS_WIN)
@@ -34,7 +35,17 @@ static base::WeakPtr<gpu::gles2::GLES2Decoder> GetEmptyGLES2Decoder() {
   NOTREACHED() << "VDA requests a GLES2Decoder, but client did not provide it";
   return base::WeakPtr<gpu::gles2::GLES2Decoder>();
 }
+
+const gpu::GpuPreferences GetGpuPreferences() {
+  GpuChildThread* gpu_child_thread = GpuChildThread::current();
+
+  // No GpuChildThread if unit test.
+  if (!gpu_child_thread)
+    return gpu::GpuPreferences();
+
+  return gpu_child_thread->gpu_preferences();
 }
+}  // namespace
 
 // static
 scoped_ptr<GpuVideoDecodeAcceleratorFactoryImpl>
@@ -61,8 +72,8 @@ GpuVideoDecodeAcceleratorFactoryImpl::CreateWithGLES2Decoder(
 
 // static
 gpu::VideoDecodeAcceleratorCapabilities
-GpuVideoDecodeAcceleratorFactoryImpl::GetDecoderCapabilities(
-    const gpu::GpuPreferences& gpu_preferences) {
+GpuVideoDecodeAcceleratorFactoryImpl::GetDecoderCapabilities() {
+  const gpu::GpuPreferences gpu_preferences = GetGpuPreferences();
   media::VideoDecodeAccelerator::Capabilities capabilities;
   if (gpu_preferences.disable_accelerated_video_decode)
     return gpu::VideoDecodeAcceleratorCapabilities();
@@ -106,9 +117,9 @@ GpuVideoDecodeAcceleratorFactoryImpl::GetDecoderCapabilities(
 scoped_ptr<media::VideoDecodeAccelerator>
 GpuVideoDecodeAcceleratorFactoryImpl::CreateVDA(
     media::VideoDecodeAccelerator::Client* client,
-    const media::VideoDecodeAccelerator::Config& config,
-    const gpu::GpuPreferences& gpu_preferences) {
+    const media::VideoDecodeAccelerator::Config& config) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  const gpu::GpuPreferences gpu_preferences = GetGpuPreferences();
 
   if (gpu_preferences.disable_accelerated_video_decode)
     return nullptr;