Remove AppListMixer field trial.

ui/app_list/search/mixer.h

Index: ui/app_list/search/mixer.h
diff --git a/ui/app_list/search/mixer.h b/ui/app_list/search/mixer.h
index b7898d733402690a8c9e49dc145312395526e752..e0aa3bd43507665d8ab9936b22a402c4e38fb806 100644
--- a/ui/app_list/search/mixer.h
+++ b/ui/app_list/search/mixer.h
@@ -28,30 +28,18 @@ class SearchResult;
 // Mixer collects results from providers, sorts them and publishes them to the
 // SearchResults UI model. The targeted results have 6 slots to hold the
 // result. The search controller can specify any number of groups, each with a
-// different number of results and priority boost. The "omnibox" group is
-// expected to contain omnibox results, and will be treated specially.
+// different number of results and priority boost.
 class APP_LIST_EXPORT Mixer {
  public:
   explicit Mixer(AppListModel::SearchResults* ui_results);
   ~Mixer();
 
-  // Adds a new mixer group. A maximum of |max_results| results will be
-  // displayed from this group (if 0, will allow unlimited results from this
-  // group). Behaviour depends on the AppListMixer field trial:
-  // - If default: Each result in the group will have its score boosted by
-  //   |boost|. |multiplier| is ignored.
-  // - If "Blended": |max_results| is a "soft" maximum; if there aren't enough
-  //   results from all groups, more than |max_results| may be chosen from this
-  //   group. Each result in the group will have its score multiplied by
-  //   |multiplier|. |boost| is ignored.
-  // Returns the group's group_id.
-  size_t AddGroup(size_t max_results, double boost, double multiplier);
-
-  // Adds a new mixer group for the special "omnibox" group. This group will be
-  // treated specially by the Mixer (it will be truncated such that it fills the
-  // remaining slots without overflowing, but with at least one result). A
-  // maximum of one group should be added using this method.
-  size_t AddOmniboxGroup(size_t max_results, double boost, double multiplier);
+  // Adds a new mixer group. A "soft" maximum of |max_results| results will be
+  // chosen from this group (if 0, will allow unlimited results from this
+  // group). If there aren't enough results from all groups, more than
+  // |max_results| may be chosen from this group. Each result in the group will
+  // have its score multiplied by |multiplier|. Returns the group's group_id.
+  size_t AddGroup(size_t max_results, double multiplier);
 
   // Associates a provider with a mixer group.
   void AddProviderToGroup(size_t group_id, SearchProvider* provider);
@@ -94,14 +82,6 @@ class APP_LIST_EXPORT Mixer {
   AppListModel::SearchResults* ui_results_;  // Not owned.
   Groups groups_;
 
-  // The ID of the omnibox group. The group with this ID will be treated
-  // specially by the Mixer. Ignored if the AppListMixer field trial is
-  // "Blended".
-  // TODO(mgiuca): Remove this after the field trial is complete.
-  size_t omnibox_group_ = 0;
-  // Whether |omnibox_group_| has been set.
-  bool has_omnibox_group_ = false;
-
   DISALLOW_COPY_AND_ASSIGN(Mixer);
 };