content: Move shader cache factory singleton into a separate file.

content/browser/gpu/gpu_process_host.cc

Index: content/browser/gpu/gpu_process_host.cc
diff --git a/content/browser/gpu/gpu_process_host.cc b/content/browser/gpu/gpu_process_host.cc
index df3d6127eaf4e69a22de01759c814eacbc400937..6ff45f7f28a2c28c0a21bc3dbf02a4695c37442d 100644
--- a/content/browser/gpu/gpu_process_host.cc
+++ b/content/browser/gpu/gpu_process_host.cc
@@ -31,7 +31,7 @@
 #include "content/browser/gpu/compositor_util.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
-#include "content/browser/gpu/shader_disk_cache.h"
+#include "content/browser/gpu/shader_cache_factory.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/service_manager/service_manager_context.h"
 #include "content/common/child_process_host_impl.h"
@@ -1172,7 +1172,7 @@ void GpuProcessHost::CreateChannelCache(int32_t client_id) {
   TRACE_EVENT0("gpu", "GpuProcessHost::CreateChannelCache");
 
   scoped_refptr<ShaderDiskCache> cache =
-      ShaderCacheFactory::GetInstance()->Get(client_id);
+      GetShaderCacheFactorySingleton()->Get(client_id);
   if (!cache.get())
     return;