diff --git a/LayoutTests/ChangeLog b/LayoutTests/ChangeLog
index e7cc1d1c0d1..39a3c7d74ee 100644
--- a/LayoutTests/ChangeLog
+++ b/LayoutTests/ChangeLog
@@ -1,3 +1,13 @@
+2012-11-22  Kent Tamura  <tkent@chromium.org>
+
+        INPUT_MULTIPLE_FIELDS_UI: Refactoring: Do not call updateInnerTextValue if only read-only sub-fields have values
+        https://bugs.webkit.org/show_bug.cgi?id=103033
+
+        Reviewed by Kentaro Hara.
+
+        * fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty-expected.txt:
+        * fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html:
+
 2012-11-22  Keishi Hattori  <keishi@webkit.org>
 
         Add week-multiple-fields tests
diff --git a/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty-expected.txt b/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty-expected.txt
index 8ed3b45356b..a7bb2bbd43f 100644
--- a/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty-expected.txt
+++ b/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty-expected.txt
@@ -6,6 +6,13 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 Empty text: --:-- --
 PASS eventSender.keyDown("upArrow"); getUserAgentShadowTextContent(input) is not emptyText
 PASS input.value = ""; getUserAgentShadowTextContent(input) is emptyText
+
+Initial text: --:--:45 --
+Empty value should not clear read-only fields.
+PASS input.value = ""; getUserAgentShadowTextContent(input) is "--:--:45 --"
+Empty value should clear only editable fields.
+PASS eventSender.keyDown("upArrow"); getUserAgentShadowTextContent(input) is "01:--:45 --"
+PASS input.value = ""; getUserAgentShadowTextContent(input) is "--:--:45 --"
 PASS successfullyParsed is true
 
 TEST COMPLETE
diff --git a/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html b/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html
index c57c89aec91..af3a31bf1c8 100644
--- a/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html
+++ b/LayoutTests/fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html
@@ -5,6 +5,23 @@
 <script src="../resources/multiple-fields-value-set-empty.js"></script>
 <script>
 testSettingEmptyStringClearsSubFields('time');
+
+debug('');
+input = document.createElement('input');
+input.type = 'time';
+input.min = '11:23:45';
+input.step = '60';
+// Because the step value is 60 seconds, the seconds fields is read-only.
+document.body.appendChild(input);
+debug('Initial text: ' + getUserAgentShadowTextContent(input));
+debug('Empty value should not clear read-only fields.');
+shouldBeEqualToString('input.value = ""; getUserAgentShadowTextContent(input)', '--:--:45 --');
+
+debug('Empty value should clear only editable fields.');
+input.focus();
+shouldBeEqualToString('eventSender.keyDown("upArrow"); getUserAgentShadowTextContent(input)', '01:--:45 --');
+shouldBeEqualToString('input.value = ""; getUserAgentShadowTextContent(input)', '--:--:45 --');
+
 </script>
 <script src="../../js/resources/js-test-post.js"></script>
 </body>
diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 82bade2f1fc..38a448fd0cd 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,29 @@
+2012-11-22  Kent Tamura  <tkent@chromium.org>
+
+        INPUT_MULTIPLE_FIELDS_UI: Refactoring: Do not call updateInnerTextValue if only read-only sub-fields have values
+        https://bugs.webkit.org/show_bug.cgi?id=103033
+
+        Reviewed by Kentaro Hara.
+
+        input[type=time] can have read-only sub fields. If only read-only fields
+        have values, we don't need to call updateInnerTextValue when
+        HTMLInputElement::value is set to "".
+
+        Tests: this patch doesn't change any visible behavior, but we add test cases to
+        fast/forms/time-multiple-fields/time-multiple-fields-value-set-empty.html
+        just in case.
+
+        * html/shadow/DateTimeEditElement.h:
+        (DateTimeEditElement): Declare anyEditableFieldsHaveValues.
+        * html/shadow/DateTimeEditElement.cpp:
+        (WebCore::DateTimeEditElement::anyEditableFieldsHaveValues):
+        Added. This function checks value existence against only editable sub-fields.
+        * html/BaseMultipleFieldsDateAndTimeInputType.cpp:
+        (WebCore::BaseMultipleFieldsDateAndTimeInputType::setValue):
+        Call DateTimeEditElement::anyEditableFieldsHaveValues() instead of
+        DateTimeFieldsState::hasAnyValue().
+        * html/DateTimeFieldsState.h: Remove hasAnyValue.
+
 2012-11-22  Allan Sandfeld Jensen  <allan.jensen@digia.com>
 
         [Qt] Lookup mimetypes using QMimeDatabase
diff --git a/Source/WebCore/html/BaseMultipleFieldsDateAndTimeInputType.cpp b/Source/WebCore/html/BaseMultipleFieldsDateAndTimeInputType.cpp
index addc8063a8b..4bd7cde2c54 100644
--- a/Source/WebCore/html/BaseMultipleFieldsDateAndTimeInputType.cpp
+++ b/Source/WebCore/html/BaseMultipleFieldsDateAndTimeInputType.cpp
@@ -325,7 +325,7 @@ FormControlState BaseMultipleFieldsDateAndTimeInputType::saveFormControlState()
 void BaseMultipleFieldsDateAndTimeInputType::setValue(const String& sanitizedValue, bool valueChanged, TextFieldEventBehavior eventBehavior)
 {
     InputType::setValue(sanitizedValue, valueChanged, eventBehavior);
-    if (valueChanged || (sanitizedValue.isEmpty() && m_dateTimeEditElement && m_dateTimeEditElement->valueAsDateTimeFieldsState().hasAnyValue()))
+    if (valueChanged || (sanitizedValue.isEmpty() && m_dateTimeEditElement && m_dateTimeEditElement->anyEditableFieldsHaveValues()))
         updateInnerTextValue();
 }
 
diff --git a/Source/WebCore/html/DateTimeFieldsState.h b/Source/WebCore/html/DateTimeFieldsState.h
index a05ae59b573..2dd21954606 100644
--- a/Source/WebCore/html/DateTimeFieldsState.h
+++ b/Source/WebCore/html/DateTimeFieldsState.h
@@ -74,7 +74,6 @@ class DateTimeFieldsState {
     bool hasSecond() const { return m_second != emptyValue; }
     bool hasWeekOfYear() const { return m_weekOfYear != emptyValue; }
     bool hasYear() const { return m_year != emptyValue; }
-    bool hasAnyValue() const { return hasAMPM() || hasDayOfMonth() || hasHour() || hasMillisecond() || hasMinute() || hasMonth() || hasSecond() || hasWeekOfYear() || hasYear(); }
 
     void setAMPM(AMPMValue ampm) { m_ampm = ampm; }
     void setDayOfMonth(unsigned dayOfMonth) { m_dayOfMonth = dayOfMonth; }
diff --git a/Source/WebCore/html/shadow/DateTimeEditElement.cpp b/Source/WebCore/html/shadow/DateTimeEditElement.cpp
index e612d2f0bd2..d36ec1cc6dc 100644
--- a/Source/WebCore/html/shadow/DateTimeEditElement.cpp
+++ b/Source/WebCore/html/shadow/DateTimeEditElement.cpp
@@ -317,6 +317,15 @@ void DateTimeEditElement::addField(PassRefPtr<DateTimeFieldElement> field)
     appendChild(field);
 }
 
+bool DateTimeEditElement::anyEditableFieldsHaveValues() const
+{
+    for (size_t fieldIndex = 0; fieldIndex < m_fields.size(); ++fieldIndex) {
+        if (!m_fields[fieldIndex]->isReadOnly() && m_fields[fieldIndex]->hasValue())
+            return true;
+    }
+    return false;
+}
+
 void DateTimeEditElement::blurByOwner()
 {
     if (DateTimeFieldElement* field = focusedField())
diff --git a/Source/WebCore/html/shadow/DateTimeEditElement.h b/Source/WebCore/html/shadow/DateTimeEditElement.h
index 94cb0ac8016..17952acf559 100644
--- a/Source/WebCore/html/shadow/DateTimeEditElement.h
+++ b/Source/WebCore/html/shadow/DateTimeEditElement.h
@@ -86,6 +86,7 @@ class DateTimeEditElement : public HTMLDivElement, public DateTimeFieldElement::
 
     virtual ~DateTimeEditElement();
     void addField(PassRefPtr<DateTimeFieldElement>);
+    bool anyEditableFieldsHaveValues() const;
     void blurByOwner();
     virtual void defaultEventHandler(Event*) OVERRIDE;
     void disabledStateChanged();