Revert 232657 "GN: toolchain threading cleanup"

Broke linux clang bots:

../../tools/gn/ninja_helper_unittest.cc:20:9:error: field 'settings' will be initialized after field 'toolchain' [-Werror,-Wreorder]

This happened on your try jobs too.

> GN: toolchain threading cleanup
> 
> Remove the thread-unsafe toolchain pointer on the otherwise-threadsafe Settings object. I replaced it with the toolchain label, and moved the is_default flag from the toolchain to the Settings object.
> 
> This required that I pass the toolchain around in a few more places, but also simplifies some other cases.
> 
> I removed the toolchain prefix from Ninja rules for the default toolchain since that's not necessary any more for GYP compat.
> 
> This fixes an annoying double-free in the toolchain manager. I think my current refactor will clean this up in a later phase.
> 
> R=scottmg@chromium.org
> 
> Review URL: https://codereview.chromium.org/51693002

TBR=brettw@chromium.org

Review URL: https://codereview.chromium.org/46313006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232661 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 1 insertions, 5 deletions

diff --git a/tools/gn/item.h b/tools/gn/item.h
index 69115bd..2538c50 100644
--- a/tools/gn/item.h
+++ b/tools/gn/item.h
@@ -11,7 +11,6 @@
 
 class Config;
 class ItemNode;
-class Settings;
 class Target;
 class Toolchain;
 
@@ -19,11 +18,9 @@ class Toolchain;
 // graph.
 class Item {
  public:
-  Item(const Settings* settings, const Label& label);
+  Item(const Label& label);
   virtual ~Item();
 
-  const Settings* settings() const { return settings_; }
-
   // This is guaranteed to never change after construction so this can be
   // accessed from any thread with no locking once the item is constructed.
   const Label& label() const { return label_; }
@@ -52,7 +49,6 @@ class Item {
   virtual void OnResolved() {}
 
  private:
-  const Settings* settings_;
   Label label_;
 
   ItemNode* item_node_;