Revert of Get rid of gpu related switches by passing gpu::GpuPreferences via IPC.

content/browser/gpu/gpu_process_host.h

Index: content/browser/gpu/gpu_process_host.h
diff --git a/content/browser/gpu/gpu_process_host.h b/content/browser/gpu/gpu_process_host.h
index 90703a7ec59e801ad734f208254c0c0148290aad..b3f6419ae238373e1411c073a01dee86b50475b3 100644
--- a/content/browser/gpu/gpu_process_host.h
+++ b/content/browser/gpu/gpu_process_host.h
@@ -40,7 +40,6 @@
 }
 
 namespace gpu {
-struct GpuPreferences;
 struct SyncToken;
 }
 
@@ -53,7 +52,7 @@
 class ShaderDiskCache;
 
 typedef base::Thread* (*GpuMainThreadFactoryFunction)(
-    const InProcessChildThreadParams&, const gpu::GpuPreferences&);
+    const InProcessChildThreadParams&);
 
 class GpuProcessHost : public BrowserChildProcessHostDelegate,
                        public IPC::Sender,