blink: adjusts overflow-clip-margin value

It should only be set if overflow: clip is specified
along both axis.

BUG=1087667
TEST=StyleAdjusterTest.AdjustOverflow

Change-Id: I3cddaf8b1b6e5041759762284f150f28b7b7662a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463749
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817211}

third_party/blink/renderer/core/css/resolver/style_adjuster.cc

@@ -715,6 +715,13 @@ void StyleAdjuster::AdjustComputedStyle(StyleResolverState& state,
       style.OverflowY() != EOverflow::kVisible)
     AdjustOverflow(style);
 
+  // overflow-clip-margin only applies if 'overflow: clip' is set along both
+  // axis.
+  if (style.OverflowX() != EOverflow::kClip ||
+      style.OverflowY() != EOverflow::kClip) {
+    style.SetOverflowClipMargin(LayoutUnit());
+  }
+
   if (StopPropagateTextDecorations(style, element))
     style.ClearAppliedTextDecorations();
   else

third_party/blink/renderer/core/css/resolver/style_adjuster_test.cc

@@ -114,13 +114,20 @@ TEST_F(StyleAdjusterTest, AdjustOverflow) {
   ScopedOverflowClipForTest overflow_clip_feature_enabler(true);
   GetDocument().SetBaseURLOverride(KURL("http://test.com"));
   SetBodyInnerHTML(R"HTML(
-    <div id='clipauto' style='overflow-x: clip; overflow-y: auto;'>
-    <div id='autoclip' style='overflow-x: auto; overflow-y: clip;'>
-    <div id='clipclip' style='overflow-x: clip; overflow-y: clip;'>
-    <div id='visclip' style='overflow-x: visible; overflow-y: clip;'>
-    <div id='clipvis' style='overflow-x: clip; overflow-y: visible;'>
-    <div id='hiddenvis' style='overflow-x: hidden; overflow-y: visible;'>
-    <div id='vishidden' style='overflow-x: visible; overflow-y: hidden;'>
+    <div id='clipauto' style='overflow-x: clip; overflow-y: auto;
+         overflow-clip-margin: 1px;'>
+    <div id='autoclip' style='overflow-x: auto; overflow-y: clip;
+         overflow-clip-margin: 1px;'>
+    <div id='clipclip' style='overflow-x: clip; overflow-y: clip;
+         overflow-clip-margin: 1px;'>
+    <div id='visclip' style='overflow-x: visible; overflow-y: clip;
+         overflow-clip-margin: 1px;'>
+    <div id='clipvis' style='overflow-x: clip; overflow-y: visible;
+         overflow-clip-margin: 1px;'>
+    <div id='hiddenvis' style='overflow-x: hidden; overflow-y: visible;
+         overflow-clip-margin: 1px;'>
+    <div id='vishidden' style='overflow-x: visible; overflow-y: hidden;
+         overflow-clip-margin: 1px;'>
     </div>
   )HTML");
   UpdateAllLifecyclePhasesForTest();
@@ -129,36 +136,43 @@ TEST_F(StyleAdjusterTest, AdjustOverflow) {
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kHidden, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kAuto, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("autoclip");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kAuto, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kHidden, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("clipclip");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kClip, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kClip, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(1), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("visclip");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kVisible, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kClip, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("clipvis");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kClip, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kVisible, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("vishidden");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kAuto, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kHidden, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 
   target = GetDocument().getElementById("hiddenvis");
   ASSERT_TRUE(target);
   EXPECT_EQ(EOverflow::kHidden, target->GetComputedStyle()->OverflowX());
   EXPECT_EQ(EOverflow::kAuto, target->GetComputedStyle()->OverflowY());
+  EXPECT_EQ(LayoutUnit(), target->GetComputedStyle()->OverflowClipMargin());
 }
 
 TEST_F(StyleAdjusterTest, SetListenerForContentEditableArea) {