[chromium] Pass SkBitmap by reference in WebImageLayer::setBitmap

cc/blink/web_image_layer_impl.cc

Index: cc/blink/web_image_layer_impl.cc
diff --git a/cc/blink/web_image_layer_impl.cc b/cc/blink/web_image_layer_impl.cc
index b31d890dc2c618390850ece816ede74b0cea8259..ee80ca6a044a76ed242d2eb84985381e206e68d1 100644
--- a/cc/blink/web_image_layer_impl.cc
+++ b/cc/blink/web_image_layer_impl.cc
@@ -25,7 +25,7 @@ blink::WebLayer* WebImageLayerImpl::layer() {
   return layer_.get();
 }
 
-void WebImageLayerImpl::setBitmap(SkBitmap bitmap) {
+void WebImageLayerImpl::setImageBitmap(const SkBitmap& bitmap) {
   if (WebLayerImpl::UsingPictureLayer()) {
     static_cast<cc::PictureImageLayer*>(layer_->layer())->SetBitmap(bitmap);
     static_cast<WebLayerImplFixedBounds*>(layer_.get())