gfx: Rename canvas SaveAndUnscale to UnscaleTheDeviceScaleFactor.

ui/gfx/canvas.cc

Index: ui/gfx/canvas.cc
diff --git a/ui/gfx/canvas.cc b/ui/gfx/canvas.cc
index 2465cfae1bc9d775eb0fabe5d4f09097422e39a2..b81f995d0cb5baf93dfeb9d5d2834cd4ec4c8bed 100644
--- a/ui/gfx/canvas.cc
+++ b/ui/gfx/canvas.cc
@@ -175,17 +175,16 @@ void Canvas::DrawDashedRect(const Rect& rect, SkColor color) {
            paint);
 }
 
-void Canvas::Save() {
-  canvas_->save();
-}
-
-float Canvas::SaveAndUnscale() {
-  Save();
+float Canvas::UndoDeviceScaleFactor() {
   SkScalar scale_factor = 1.0f / image_scale_;
   canvas_->scale(scale_factor, scale_factor);
   return image_scale_;
 }
 
+void Canvas::Save() {
+  canvas_->save();
+}
+
 void Canvas::SaveLayerAlpha(uint8 alpha) {
   canvas_->saveLayerAlpha(NULL, alpha);
 }