Use GpuPreferences to avoid directly accessing switches in gpu related code

gpu/command_buffer/service/context_group.h

Index: gpu/command_buffer/service/context_group.h
diff --git a/gpu/command_buffer/service/context_group.h b/gpu/command_buffer/service/context_group.h
index 86c239e93b9ca051bd1cdc6c96be20ffac8851a3..3641d1afe5036889ac9eee83a7f1c099d7e566f2 100644
--- a/gpu/command_buffer/service/context_group.h
+++ b/gpu/command_buffer/service/context_group.h
@@ -18,11 +18,13 @@
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/framebuffer_completeness_cache.h"
+#include "gpu/command_buffer/service/gpu_preferences.h"
 #include "gpu/command_buffer/service/shader_translator_cache.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
 
+struct GpuPreferences;
 class TransferBufferManager;
 class ValueStateMap;
 
@@ -49,6 +51,7 @@ struct DisallowedFeatures;
 class GPU_EXPORT ContextGroup : public base::RefCounted<ContextGroup> {
  public:
   ContextGroup(
+      const GpuPreferences& gpu_preferences,
       const scoped_refptr<MailboxManager>& mailbox_manager,
       const scoped_refptr<MemoryTracker>& memory_tracker,
       const scoped_refptr<ShaderTranslatorCache>& shader_translator_cache,
@@ -122,6 +125,10 @@ class GPU_EXPORT ContextGroup : public base::RefCounted<ContextGroup> {
     return feature_info_.get();
   }
 
+  const GpuPreferences& gpu_preferences() const {
+    return gpu_preferences_;
+  }
+
   BufferManager* buffer_manager() const {
     return buffer_manager_.get();
   }
@@ -232,6 +239,7 @@ class GPU_EXPORT ContextGroup : public base::RefCounted<ContextGroup> {
   bool QueryGLFeatureU(GLenum pname, GLint min_required, uint32_t* v);
   bool HaveContexts();
 
+  const GpuPreferences& gpu_preferences_;
   scoped_refptr<MailboxManager> mailbox_manager_;
   scoped_refptr<MemoryTracker> memory_tracker_;
   scoped_refptr<ShaderTranslatorCache> shader_translator_cache_;