HTMLTextAreaElement.setSelectionRange should not change focus.

Source/core/html/HTMLTextAreaElement.cpp

Index: Source/core/html/HTMLTextAreaElement.cpp
diff --git a/Source/core/html/HTMLTextAreaElement.cpp b/Source/core/html/HTMLTextAreaElement.cpp
index f0ba03afd35d1ce1f43aa75fcfee22ee89c688bd..631ab4e063ac4e0d0f2925df0afd9791b76842a1 100644
--- a/Source/core/html/HTMLTextAreaElement.cpp
+++ b/Source/core/html/HTMLTextAreaElement.cpp
@@ -336,9 +336,16 @@ String HTMLTextAreaElement::value() const
 void HTMLTextAreaElement::setValue(const String& value, TextFieldEventBehavior eventBehavior)
 {
     RefPtrWillBeRawPtr<HTMLTextAreaElement> protector(this);
-    setValueCommon(value, eventBehavior);
+    bool isUpdated = setValueCommon(value, eventBehavior);
     m_isDirty = true;
     setNeedsValidityCheck();
+
+    if (isUpdated) {
+        // Set the caret to the end of the text value.
+        unsigned endOfString = m_value.length();
+        setSelectionRange(endOfString, endOfString);
+    }
+
     if (document().focusedElement() == this)
         document().frameHost()->chrome().client().didUpdateTextOfFocusedElementByNonUserInput();
 }
@@ -350,7 +357,7 @@ void HTMLTextAreaElement::setNonDirtyValue(const String& value)
     setNeedsValidityCheck();
 }
 
-void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventBehavior eventBehavior)
+bool HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventBehavior eventBehavior)
 {
     // Code elsewhere normalizes line endings added by the user via the keyboard or pasting.
     // We normalize line endings coming from JavaScript here.
@@ -361,7 +368,7 @@ void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventB
     // Return early because we don't want to move the caret or trigger other side effects
     // when the value isn't changing. This matches Firefox behavior, at least.
     if (normalizedValue == value())
-        return;
+        return false;
 
     m_value = normalizedValue;
     setInnerEditorValue(m_value);
@@ -371,12 +378,6 @@ void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventB
     setNeedsStyleRecalc(SubtreeStyleChange);
     m_suggestedValue = String();
 
-    // Set the caret to the end of the text value.
-    if (document().focusedElement() == this) {
-        unsigned endOfString = m_value.length();
-        setSelectionRange(endOfString, endOfString);
-    }
-
     notifyFormStateChanged();
     if (eventBehavior == DispatchNoEvent) {
         setTextAsOfLastFormControlChangeEvent(normalizedValue);
@@ -385,6 +386,7 @@ void HTMLTextAreaElement::setValueCommon(const String& newValue, TextFieldEventB
             dispatchFormControlInputEvent();
         dispatchFormControlChangeEvent();
     }
+    return true;
 }
 
 void HTMLTextAreaElement::setInnerEditorValue(const String& value)