Move Singleton and related structs to namespace base

skia/ext/skia_memory_dump_provider.cc

Index: skia/ext/skia_memory_dump_provider.cc
diff --git a/skia/ext/skia_memory_dump_provider.cc b/skia/ext/skia_memory_dump_provider.cc
index aec9b905e7eb20400b6554ec6ffc2cfa5281b16b..9eb4e0c772e48a75e1c5aa26d5b5cab7628b00ab 100644
--- a/skia/ext/skia_memory_dump_provider.cc
+++ b/skia/ext/skia_memory_dump_provider.cc
@@ -14,8 +14,9 @@ namespace skia {
 
 // static
 SkiaMemoryDumpProvider* SkiaMemoryDumpProvider::GetInstance() {
-  return Singleton<SkiaMemoryDumpProvider,
-                   LeakySingletonTraits<SkiaMemoryDumpProvider>>::get();
+  return base::Singleton<
+      SkiaMemoryDumpProvider,
+      base::LeakySingletonTraits<SkiaMemoryDumpProvider>>::get();
 }
 
 SkiaMemoryDumpProvider::SkiaMemoryDumpProvider() {}