Platform/loader: Remove a stale TODO

We are not exposing |forPreload| boolean flag to FrameFetchContext
any more. So, the major concern for the TODO has already been resolved.

Bug: 675883
Change-Id: I56c33ab41dac89185a679250f71fe6a8a48d3e69
Reviewed-on: https://chromium-review.googlesource.com/923771
Commit-Queue: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537734}

third_party/WebKit/Source/platform/loader/fetch/FetchParameters.h

@@ -70,11 +70,6 @@ class PLATFORM_EXPORT FetchParameters {
     kDisallowPlaceholder = 0,  // The requested image must not be a placeholder.
     kAllowPlaceholder,         // The image is allowed to be a placeholder.
   };
-  // TODO(toyoshim): Consider to define an enum for preload options, and use it
-  // instead of bool in this class, FrameFetchContext, and so on. If it is
-  // reasonable, we try merging m_speculativePreload and m_linkPreload into one
-  // enum type. See https://crbug.com/675883.
-
   struct ResourceWidth {
     DISALLOW_NEW();
     float width;