ui/gfx: Get rid of a few static variables from NativeTheme* type.

ui/gfx/native_theme_linux.cc

Index: ui/gfx/native_theme_linux.cc
diff --git a/ui/gfx/native_theme_linux.cc b/ui/gfx/native_theme_linux.cc
index 5ab5fb0ebaed71bebd62adea69e2f4b0ae51a144..2a3f6dad68358b48f7c4c909e2bdae471250e568 100644
--- a/ui/gfx/native_theme_linux.cc
+++ b/ui/gfx/native_theme_linux.cc
@@ -6,6 +6,7 @@
 
 #include <limits>
 
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "grit/gfx_resources.h"
 #include "third_party/skia/include/effects/SkGradientShader.h"
@@ -43,19 +44,27 @@ const NativeTheme* NativeTheme::instance() {
   return NativeThemeLinux::instance();
 }
 
+static base::LazyInstance<NativeThemeLinux> g_native_theme(
+    base::LINKER_INITIALIZED);
+
+NativeThemeLinux::NativeThemeLinux() {
+}
+
+NativeThemeLinux::~NativeThemeLinux() {
+}
+
 #if !defined(OS_CHROMEOS)
 // Chromeos has a different look.
 // static
 const NativeThemeLinux* NativeThemeLinux::instance() {
-  // The global NativeThemeLinux instance.
-  static NativeThemeLinux s_native_theme;
-  return &s_native_theme;
+  return g_native_theme.Pointer();
 }
 #endif
 
 // Get lightness adjusted color.
-static SkColor BrightenColor(const color_utils::HSL& hsl, SkAlpha alpha,
-    double lightness_amount) {
+static SkColor BrightenColor(const color_utils::HSL& hsl,
+                             SkAlpha alpha,
+                             double lightness_amount) {
   color_utils::HSL adjusted = hsl;
   adjusted.l += lightness_amount;
   if (adjusted.l > 1.0)
@@ -66,12 +75,6 @@ static SkColor BrightenColor(const color_utils::HSL& hsl, SkAlpha alpha,
   return color_utils::HSLToSkColor(adjusted, alpha);
 }
 
-NativeThemeLinux::NativeThemeLinux() {
-}
-
-NativeThemeLinux::~NativeThemeLinux() {
-}
-
 gfx::Size NativeThemeLinux::GetPartSize(Part part,
                                         State state,
                                         const ExtraParams& extra) const {