DevTools: allow codemirror softundo to work on readonly files

third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js

Index: third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
diff --git a/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js b/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
index 51bc5562847791c2893962fcfa54ffad9ced9824..da1cb2c41dc2e3d6782ac2f2cef15bdc771b36a5 100644
--- a/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
+++ b/third_party/WebKit/Source/devtools/front_end/source_frame/CodeMirrorTextEditor.js
@@ -964,6 +964,24 @@ WebInspector.CodeMirrorTextEditor.prototype = {
     },
 
     /**
+     * @param {string} key
+     * @param {*} value
+     */
+    setState: function(key, value)

[lushnikov, 2016/06/27 15:47:52]

why is this public?

+    {
+        if (this._codeMirror.state)
+            this._codeMirror.state[key] = value;

[lushnikov, 2016/06/27 15:47:52]

the "codeMirror.state" seems to be a part of CM internals (i'm not sure why it
is exposed). We should not use it

+    },
+
+    /**
+     * @return {!Object}
+     */
+    getState: function()
+    {
+        return this._codeMirror.state || {};
+    },
+
+    /**
      * @param {boolean} readOnly
      */
     setReadOnly: function(readOnly)
@@ -2053,9 +2071,12 @@ WebInspector.CodeMirrorTextEditor.SelectNextOccurrenceController.prototype = {
 
     undoLastSelection: function()
     {
+        var wasSuppressingEdits = this._textEditor.getState()["suppressEdits"];
+        this._textEditor.setState("suppressEdits", false);
         this._muteSelectionListener = true;
         this._codeMirror.execCommand("undoSelection");
         this._muteSelectionListener = false;
+        this._textEditor.setState("suppressEdits", wasSuppressingEdits);
     },
 
     selectNextOccurrence: function()