Revert of Content in disabled input field should not be selectable. (…

…patchset #4 id:80001 of https://codereview.chromium.org/2145323002/ )

Reason for revert:
It caused regression:
https://bugs.chromium.org/p/chromium/issues/detail?id=656736

Original issue's description:
> Content in disabled input field should not be selectable.
>
> Spec: https://html.spec.whatwg.org/multipage/forms.html#the-readonly-attribute:attr-input-readonly
>
> BUG=626581
>
> Committed: https://crrev.com/21d670d3e740b26dcdf63631d163c45a57d9531c
> Cr-Commit-Position: refs/heads/master@{#405717}

TBR=tkent@chromium.org,ramya.v@samsung.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=626581

Review-Url: https://codereview.chromium.org/2455853002
Cr-Commit-Position: refs/heads/master@{#428261}

third_party/WebKit/LayoutTests/editing/selection/readonly-disabled-text-selection-expected.txt

@@ -3,10 +3,10 @@ PASS successfullyParsed is true
 TEST COMPLETE
 PASS window.getSelection().toString() is "NormalInput"
 PASS window.getSelection().toString() is "ReadonlyInput"
-PASS window.getSelection().toString() is ""
-PASS window.getSelection().toString() is ""
+PASS window.getSelection().toString() is "DisabledInput"
+PASS window.getSelection().toString() is "ReadonlyDisabledInput"
 PASS window.getSelection().toString() is "NormalTextarea"
 PASS window.getSelection().toString() is "ReadonlyTextarea"
-PASS window.getSelection().toString() is ""
-PASS window.getSelection().toString() is ""
+PASS window.getSelection().toString() is "DisabledTextarea"
+PASS window.getSelection().toString() is "ReadonlyDisabledTextarea"
 

third_party/WebKit/LayoutTests/editing/selection/readonly-disabled-text-selection.html

@@ -5,7 +5,7 @@
     if (!window.eventSender || !window.eventSender.gestureLongPress) {
         debug("gestureLongPress not implemented by this platform.");
         debug("Manullay long press on every element in the page and check whether Text selection is happening or not");
-        debug("If Text selection is not happening for readonly input/textarea, then it's a failure.");
+        debug("If Text selection is not happening for readonly or disabled input/textarea, then it's a failure.");
         return;
     }
 
@@ -37,10 +37,10 @@
 </script>
 <input id="normalText" type="text" value="NormalInput">
 <input id="readOnlyText" type="text" value="ReadonlyInput" readonly>
-<input id="disabledText" type="text" value="" disabled>
-<input id="readOnlyDisabledText" size="20" type="text" value=""readonly disabled>
+<input id="disabledText" type="text" value="DisabledInput" disabled>
+<input id="readOnlyDisabledText" size="20" type="text" value="ReadonlyDisabledInput"readonly disabled>
 <textarea id="normalTextArea" cols="31">NormalTextarea</textarea>
 <textarea id="readOnlyTextArea" cols="31" readonly>ReadonlyTextarea</textarea>
-<textarea id="disabledTextArea" cols="31" disabled></textarea>
-<textarea id="readOnlyDisabledTextArea" cols="31" readonly disabled></textarea>
+<textarea id="disabledTextArea" cols="31" disabled>DisabledTextarea</textarea>
+<textarea id="readOnlyDisabledTextArea" cols="31" readonly disabled>ReadonlyDisabledTextarea</textarea>
 

third_party/WebKit/LayoutTests/fast/forms/input-readonly-select-expected.txt

@@ -5,7 +5,7 @@ double clicking on readonly input
 PASS selectEventFiredOnReadonlyInput is true
 
 double clicking on disabled input
-PASS selectEventFiredOnDisabledInput is false
+PASS selectEventFiredOnDisabledInput is true
 
 double clicking on normal textarea
 PASS selectEventFiredOnTextarea is true
@@ -14,7 +14,7 @@ double clicking on readonly textarea
 PASS selectEventFiredOnReadonlyTextarea is true
 
 double clicking on disabled textarea
-PASS selectEventFiredOnDisabledTextarea is false
+PASS selectEventFiredOnDisabledTextarea is true
 
 PASS successfullyParsed is true
 

third_party/WebKit/LayoutTests/fast/forms/input-readonly-select.html

@@ -65,7 +65,7 @@
 
 debug('double clicking on disabled input');
 doubleClickOn(disabledInput);
-shouldBeFalse('selectEventFiredOnDisabledInput');
+shouldBeTrue('selectEventFiredOnDisabledInput');
 debug('');
 
 debug('double clicking on normal textarea');
@@ -80,7 +80,7 @@
 
 debug('double clicking on disabled textarea');
 doubleClickOn(disabledTextarea);
-shouldBeFalse('selectEventFiredOnDisabledTextarea');
+shouldBeTrue('selectEventFiredOnDisabledTextarea');
 debug('');
 
 container.innerHTML = "";

third_party/WebKit/Source/core/dom/Node.cpp

@@ -961,9 +961,6 @@ int Node::maxCharacterOffset() const {
 // FIXME: Shouldn't these functions be in the editing code?  Code that asks
 // questions about HTML in the core DOM class is obviously misplaced.
 bool Node::canStartSelection() const {
-  if (isDisabledFormControl(this))
-    return false;
-
   if (hasEditableStyle(*this))
     return true;
 

third_party/WebKit/Source/core/editing/SelectionController.cpp

@@ -846,8 +846,9 @@ bool SelectionController::handleGestureLongPress(
   if (!innerNode)
     return false;
   innerNode->document().updateStyleAndLayoutTree();
-  bool innerNodeIsSelectable =
-      hasEditableStyle(*innerNode) || innerNode->canStartSelection();
+  bool innerNodeIsSelectable = hasEditableStyle(*innerNode) ||
+                               innerNode->isTextNode() ||
+                               innerNode->canStartSelection();
   if (!innerNodeIsSelectable)
     return false;