SetBackground{X/Y}Origin after BackgroundPosition{X/Y}::ApplyInherit SetPosition{X/Y}

BackgroundPosition{X/Y}::ApplyInherit only SetPosition{X/Y}(),
Background{X/Y}Origin are not set. We should make them set.

Bug: 819119
Signed-off-by: Zhuoyu Qian <zhuoyu.qian@samsung.com>
Change-Id: Ic7d37e95c5cb91f4d613f0455d0ed7e7e8e16a24
Reviewed-on: https://chromium-review.googlesource.com/961765Reviewed-by: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543307}

third_party/WebKit/LayoutTests/fast/css/background-position-inherit-expected.txt

 This tests that background-position: inherit is applied correctly.
 
 PASS
+PASS
+PASS

third_party/WebKit/LayoutTests/fast/css/background-position-inherit.html

 <div style="background-position: 25% 75%">
     <div id="target" style="background-position: inherit;"></div>
 </div>
+<div style="background-position: right 25% bottom 75%">
+    <div id="target2" style="background-position: inherit;"></div>
+</div>
+<div style="background-position: bottom 75% right 25%">
+    <div id="target3" style="background-position: inherit;"></div>
+</div>
 <p>
     This tests that <tt>background-position: inherit</tt> is applied correctly.
 </p>
@@ -11,6 +17,16 @@
         testRunner.dumpAsText();
 
     var targetBackgroundPosition = getComputedStyle(document.getElementById("target")).backgroundPosition,cssText;
+    var result = document.getElementById("result");
+
+    result.innerText = targetBackgroundPosition == "25% 75%" ? "PASS" : "FAIL: The inherited value was " + targetBackgroundPosition;
+    result.innerText += "\n";
+
+    var targetBackgroundPosition2 = getComputedStyle(document.getElementById("target2")).backgroundPosition,cssText;
+    result.innerText += targetBackgroundPosition2 == "right 25% bottom 75%" ? "PASS" : "FAIL: The inherited value was " + targetBackgroundPosition;
+    result.innerText += "\n";
+
+    var targetBackgroundPosition3 = getComputedStyle(document.getElementById("target3")).backgroundPosition,cssText;
+    result.innerText += targetBackgroundPosition3 == "right 25% bottom 75%" ? "PASS" : "FAIL: The inherited value was " + targetBackgroundPosition;
 
-    document.getElementById("result").innerText = targetBackgroundPosition == "25% 75%" ? "PASS" : "FAIL: The inherited value was " + targetBackgroundPosition;
 </script>

third_party/WebKit/Source/build/scripts/core/css/properties/templates/CSSPropertySubclass.cpp.tmpl

@@ -33,6 +33,14 @@ namespace CSSLonghand {
     if (!currChild)
       currChild = prevChild->EnsureNext();
     currChild->Set{{fill_type}}(currParent->{{property.custom_apply_args['fill_type_getter']}}());
+    {% if fill_type == "PositionX" %}
+    if (currParent->IsBackgroundXOriginSet())
+      currChild->SetBackgroundXOrigin(currParent->BackgroundXOrigin());
+    {% endif %}
+    {% if fill_type == "PositionY" %}
+    if (currParent->IsBackgroundYOriginSet())
+      currChild->SetBackgroundYOrigin(currParent->BackgroundYOrigin());
+    {% endif %}
     prevChild = currChild;
     currChild = prevChild->Next();
     currParent = currParent->Next();