gfx: Make conversions from Size to SizeF be explicit.

chrome/browser/android/compositor/layer/thumbnail_layer.cc

Index: chrome/browser/android/compositor/layer/thumbnail_layer.cc
diff --git a/chrome/browser/android/compositor/layer/thumbnail_layer.cc b/chrome/browser/android/compositor/layer/thumbnail_layer.cc
index b18555ac593fe9416546bf2e670d1fc9d5b93d0d..6be1445f3400f53013d56285edb2b08fe34e68ca 100644
--- a/chrome/browser/android/compositor/layer/thumbnail_layer.cc
+++ b/chrome/browser/android/compositor/layer/thumbnail_layer.cc
@@ -24,9 +24,8 @@ void ThumbnailLayer::SetThumbnail(Thumbnail* thumbnail) {
 
 void ThumbnailLayer::Clip(const gfx::Rect& clipping) {
   last_clipping_ = clipping;
-  gfx::Size clipped_content =
-      gfx::ToCeiledSize(gfx::Size(content_size_.width() - clipping.x(),
-                                  content_size_.height() - clipping.y()));
+  gfx::Size clipped_content = gfx::Size(content_size_.width() - clipping.x(),
+                                        content_size_.height() - clipping.y());
   clipped_content.SetToMin(clipping.size());
   layer_->SetBounds(clipped_content);