Updates subpixel positioning and hinting when DSF is changed

ui/gfx/font_render_params.cc

Index: ui/gfx/font_render_params.cc
diff --git a/ui/gfx/font_render_params.cc b/ui/gfx/font_render_params.cc
index 780489172b04f18d3d0f20b8cc567e7bef071511..521d1c73b526660d535d4062bdc7f6e5bff319ed 100644
--- a/ui/gfx/font_render_params.cc
+++ b/ui/gfx/font_render_params.cc
@@ -6,6 +6,32 @@
 
 namespace gfx {
 
+namespace {
+
+FontRenderParamsRewriter* g_instance = nullptr;
+}
+
+// static
+FontRenderParamsRewriter* FontRenderParamsRewriter::GetInstance() {
+  return g_instance;
+}
+
+// static
+void FontRenderParamsRewriter::SetInstance(FontRenderParamsRewriter* instance) {
+  Shutdown();
+  g_instance = instance;
+}
+
+// static
+void FontRenderParamsRewriter::Shutdown() {
+  if (g_instance)
+    delete g_instance;
+  g_instance = nullptr;
+}
+
+FontRenderParamsRewriter::~FontRenderParamsRewriter() {
+}
+
 FontRenderParams::FontRenderParams()
     : antialiasing(true),
       subpixel_positioning(true),
@@ -26,4 +52,12 @@ FontRenderParamsQuery::FontRenderParamsQuery(bool for_web_contents)
 
 FontRenderParamsQuery::~FontRenderParamsQuery() {}
 
+FontRenderParams GetCurrentFontRenderParams(const FontRenderParamsQuery& query,
+                                            std::string* family_out) {
+  FontRenderParams params = GetSystemFontRenderParams(query, family_out);
+  if (g_instance)
+    g_instance->RewriteParams(&params);
+  return params;
+}
+
 }  // namespace gfx