[DevTools] Introduce a setting for console autocomplete from history.

third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js

Index: third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js b/third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js
index 79952d39399ba6e6c3af2f170cbf80c20f98ee92..d90672fced3670fae7295660bc0d04a639da6081 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js
@@ -814,6 +814,8 @@ WebInspector.TextPromptWithHistory = function(completions, stopCharacters)
      * @type {number}
      */
     this._historyOffset = 1;
+
+    this._addCompletionsFromHistory = true;
 }
 
 WebInspector.TextPromptWithHistory.prototype = {
@@ -833,7 +835,7 @@ WebInspector.TextPromptWithHistory.prototype = {
      */
     additionalCompletions: function(prefix)
     {
-        if (!this.isCaretAtEndOfPrompt())
+        if (!this._addCompletionsFromHistory || !this.isCaretAtEndOfPrompt())
             return [];
         var result = [];
         var text = this.text();
@@ -860,6 +862,14 @@ WebInspector.TextPromptWithHistory.prototype = {
     },
 
     /**
+     * @param {boolean} value
+     */
+    setAddCompletionsFromHistory: function(value)
+    {
+        this._addCompletionsFromHistory = value;
+    },
+
+    /**
      * Pushes a committed text into the history.
      * @param {string} text
      */