Add scale factor tag to data packs

ui/base/resource/data_pack.cc

Index: ui/base/resource/data_pack.cc
diff --git a/ui/base/resource/data_pack.cc b/ui/base/resource/data_pack.cc
index 6a8490c4deb101bbee37f134194022f5b15b892b..9b9d918eac93af6f35c6bb6275f9c546d3dddec7 100644
--- a/ui/base/resource/data_pack.cc
+++ b/ui/base/resource/data_pack.cc
@@ -61,9 +61,12 @@ enum LoadErrors {
 
 namespace ui {
 
-// In .cc for MemoryMappedFile dtor.
-DataPack::DataPack() : resource_count_(0), text_encoding_type_(BINARY) {
+DataPack::DataPack()
+    : resource_count_(0),
+      text_encoding_type_(BINARY),
+      scale_factor_(1.0) {
 }
+
 DataPack::~DataPack() {
 }
 
@@ -183,6 +186,10 @@ ResourceHandle::TextEncodingType DataPack::GetTextEncodingType() const {
   return text_encoding_type_;
 }
 
+float DataPack::GetScaleFactor() const {
+  return scale_factor_;
+}
+
 // static
 bool DataPack::WritePack(const FilePath& path,
                          const std::map<uint16, base::StringPiece>& resources,