Interpret '?' and Ctrl-K or Ctrl-E as putting omnibox in keyword search mode for Default Search Pro…

components/omnibox/browser/omnibox_edit_model.h

Index: components/omnibox/browser/omnibox_edit_model.h
diff --git a/components/omnibox/browser/omnibox_edit_model.h b/components/omnibox/browser/omnibox_edit_model.h
index 4c567c2b70e3cf59308c75253747641e020aaaf6..87af1c696ed31e3a795e463e86dfd1e4461e8890 100644
--- a/components/omnibox/browser/omnibox_edit_model.h
+++ b/components/omnibox/browser/omnibox_edit_model.h
@@ -40,6 +40,8 @@ enum EnteredKeywordModeMethod {
   ENTERED_KEYWORD_MODE_VIA_TAB = 0,
   ENTERED_KEYWORD_MODE_VIA_SPACE_AT_END = 1,
   ENTERED_KEYWORD_MODE_VIA_SPACE_IN_MIDDLE = 2,
+  ENTERED_KEYWORD_MODE_VIA_KEYBOARD_SHORTCUT = 3,
+  ENTERED_KEYWORD_MODE_VIA_QUESTION_MARK = 4,
   ENTERED_KEYWORD_MODE_NUM_ITEMS
 };
 
@@ -59,6 +61,7 @@ class OmniboxEditModel {
           const base::string16& gray_text,
           const base::string16& keyword,
           bool is_keyword_hint,
+          EnteredKeywordModeMethod keyword_entered_method,
           bool url_replacement_enabled,
           OmniboxFocusState focus_state,
           FocusSource focus_source,
@@ -71,6 +74,7 @@ class OmniboxEditModel {
     const base::string16 gray_text;
     const base::string16 keyword;
     const bool is_keyword_hint;
+    EnteredKeywordModeMethod keyword_entered_method;
     bool url_replacement_enabled;
     OmniboxFocusState focus_state;
     FocusSource focus_source;
@@ -236,11 +240,15 @@ class OmniboxEditModel {
   }
 
   // Accepts the current keyword hint as a keyword. It always returns true for
-  // caller convenience. |entered_method| indicates how the use entered
-  // keyword mode. This parameter is only used for metrics/logging; it's not
-  // used to change user-visible behavior.
+  // caller convenience. |entered_method| indicates how the user entered
+  // keyword mode.
   bool AcceptKeyword(EnteredKeywordModeMethod entered_method);
 
+  // Sets the current keyword to that of the user's default search provider and
+  // updates the view so the user sees the keyword chip in the omnibox.
+  void EnterKeywordModeForDefaultSearchProvider(
+      EnteredKeywordModeMethod keyword_entered_method);
+
   // Accepts the current temporary text as the user text.
   void AcceptTemporaryTextAsUserText();
 
@@ -335,6 +343,7 @@ class OmniboxEditModel {
                              size_t selection_end,
                              bool selection_differs,
                              bool text_differs,
+                             bool keyword_differs,
                              bool just_deleted_text,
                              bool allow_keyword_ui_change);
 
@@ -508,6 +517,11 @@ class OmniboxEditModel {
   bool just_deleted_text_;
   base::string16 inline_autocomplete_text_;
 
+  // If the user types '?' to enter keyword mode, and then presses backspace,
+  // we want a '?' to be displayed on the omnibox.  Without this variable, the
+  // user would immediately be transitioned back into keyword mode.
+  bool just_cleared_keyword_;
+
   // Used by OnPopupDataChanged to keep track of whether there is currently a
   // temporary text.
   //
@@ -546,6 +560,11 @@ class OmniboxEditModel {
   // keyword_ to show a "Press <tab> to search" sort of hint.
   bool is_keyword_hint_;
 
+  // Indicates how the user entered keyword mode if the user is actually in
+  // keyword mode.  Otherwise, the value of this variable is undefined.  This
+  // is used to restore the user's search terms upon a call to ClearKeyword().
+  EnteredKeywordModeMethod keyword_entered_method_;
+
   // This is needed to properly update the SearchModel state when the user
   // presses escape.
   bool in_revert_;