cc: Low quality support for low res tiles

cc/resources/managed_tile_state.cc

Index: cc/resources/managed_tile_state.cc
diff --git a/cc/resources/managed_tile_state.cc b/cc/resources/managed_tile_state.cc
index d137b8dd762c20ed375bf7194da2b3f8e66502fa..87940e815ef2663d56fc0054354cee789dbad87f 100644
--- a/cc/resources/managed_tile_state.cc
+++ b/cc/resources/managed_tile_state.cc
@@ -27,7 +27,8 @@ ManagedTileState::TileVersion::TileVersion()
     : mode_(RESOURCE_MODE),
       resource_id_(0),
       resource_format_(GL_RGBA),
-      forced_upload_(false) {
+      forced_upload_(false),
+      raster_mode_(INVALID_RASTER_MODE) {
 }
 
 ManagedTileState::TileVersion::~TileVersion() {
@@ -53,6 +54,22 @@ size_t ManagedTileState::TileVersion::GPUMemoryUsageInBytes() const {
   return resource_->bytes();
 }
 
+bool ManagedTileState::TileVersion::ShouldBeUpdatedBy(
+    TileRasterMode new_mode) const {
+  return new_mode > raster_mode_;
+}
+
+void ManagedTileState::TileVersion::PushPropertiesTo(TileVersion* destination) {
+  destination->mode_ = mode_;
+  destination->solid_color_ = solid_color_;
+  destination->resource_id_ = resource_ ? resource_->id() : resource_id_;
+  destination->resource_ = resource_.Pass();
+  destination->resource_format_ = resource_format_;
+  destination->forced_upload_ = forced_upload_;
+  destination->raster_mode_ = raster_mode_;
+  destination->raster_task_ = raster_task_;
+}
+
 ManagedTileState::~ManagedTileState() {
 }