[LayoutNG] Adapt LayoutInline::LinesBoundingBox() to work with fragments

This patch makes |LayoutInline::LinesBoundingBox()| to work with LayoutNG by
utilizing |NGInlineFragmentIterator| to collect box fragments associated to
|LayoutInline|.

This patch also changes |ShouldCreateBoxFragment()| to return |true| for
producing box fragements for plain SPAN to avoid using "culled inline box",
which is collected by traversing descendants of layout tree.

Note: Exclude master.tryserver.chromium.linux:linux_layout_tests_layout_ng

Bug: 591099
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_layout_ng
Change-Id: Ia71db55d551a8ee8e5e36019ab94e7fb18479198
Reviewed-on: https://chromium-review.googlesource.com/768599
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521017}

third_party/WebKit/Source/core/layout/LayoutInline.cpp

@@ -34,6 +34,7 @@
 #include "core/layout/LayoutView.h"
 #include "core/layout/api/LineLayoutBoxModel.h"
 #include "core/layout/line/InlineTextBox.h"
+#include "core/layout/ng/inline/ng_inline_fragment_iterator.h"
 #include "core/layout/ng/layout_ng_block_flow.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/InlinePainter.h"
@@ -45,6 +46,19 @@
 
 namespace blink {
 
+namespace {
+
+// TODO(layout-dev): Once we generate fragment for all inline element, we should
+// use |LayoutObject::EnclosingBlockFlowFragment()|.
+const NGPhysicalBoxFragment* EnclosingBlockFlowFragmentOf(
+    const LayoutInline& node) {
+  if (!RuntimeEnabledFeatures::LayoutNGPaintFragmentsEnabled())
+    return nullptr;
+  return node.EnclosingBlockFlowFragment();
+}
+
+}  // anonymous namespace
+
 struct SameSizeAsLayoutInline : public LayoutBoxModelObject {
   ~SameSizeAsLayoutInline() override {}
   LayoutObjectChildList children_;
@@ -953,6 +967,19 @@ class LinesBoundingBoxGeneratorContext {
 }  // unnamed namespace
 
 LayoutRect LayoutInline::LinesBoundingBox() const {
+  if (const NGPhysicalBoxFragment* box_fragment =
+          EnclosingBlockFlowFragmentOf(*this)) {
+    LayoutRect result;
+    NGInlineFragmentIterator children(*box_fragment, this);
+    for (const auto& child : children) {
+      NGPhysicalOffset left_top =
+          child.fragment->Offset() + child.offset_to_container_box;
+      result.Unite(LayoutRect(LayoutPoint(left_top.left, left_top.top),
+                              child.fragment->Size().ToLayoutSize()));
+    }
+    return result;
+  }
+
   if (!AlwaysCreateLineBoxes()) {
     DCHECK(!FirstLineBox());
     FloatRect float_result;

third_party/WebKit/Source/core/layout/LayoutInlineTest.cpp

@@ -6,12 +6,63 @@
 
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutTestHelper.h"
+#include "platform/runtime_enabled_features.h"
+#include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
 
 class LayoutInlineTest : public RenderingTest {};
 
+// Helper class to run the same test code with and without LayoutNG
+class ParameterizedLayoutInlineTest
+    : public ::testing::WithParamInterface<bool>,
+      private ScopedLayoutNGForTest,
+      private ScopedLayoutNGPaintFragmentsForTest,
+      public LayoutInlineTest {
+ public:
+  ParameterizedLayoutInlineTest()
+      : ScopedLayoutNGForTest(GetParam()),
+        ScopedLayoutNGPaintFragmentsForTest(GetParam()) {}
+
+ protected:
+  bool LayoutNGEnabled() const { return GetParam(); }
+};
+
+INSTANTIATE_TEST_CASE_P(All, ParameterizedLayoutInlineTest, ::testing::Bool());
+
+TEST_P(ParameterizedLayoutInlineTest, LinesBoundingBox) {
+  LoadAhem();
+  SetBodyInnerHTML(
+      "<style>"
+      "* { font-family: Ahem; font-size: 13px; }"
+      ".vertical { writing-mode: vertical-rl; }"
+      "</style>"
+      "<p><span id=ltr1>abc<br>xyz</span></p>"
+      "<p><span id=ltr2>12 345 6789</span></p>"
+      "<p dir=rtl><span id=rtl1>abc<br>xyz</span></p>"
+      "<p dir=rtl><span id=rtl2>12 345 6789</span></p>"
+      "<p class=vertical><span id=vertical>abc<br>xyz</span></p>");
+  EXPECT_EQ(
+      LayoutRect(LayoutPoint(0, 0), LayoutSize(39, 26)),
+      ToLayoutInline(GetLayoutObjectByElementId("ltr1"))->LinesBoundingBox());
+  EXPECT_EQ(
+      LayoutRect(LayoutPoint(0, 0), LayoutSize(143, 13)),
+      ToLayoutInline(GetLayoutObjectByElementId("ltr2"))->LinesBoundingBox());
+  EXPECT_EQ(
+      LayoutRect(LayoutPoint(745, 0), LayoutSize(39, 26)),
+      ToLayoutInline(GetLayoutObjectByElementId("rtl1"))->LinesBoundingBox());
+  // TODO(layout-dev): LayoutNG should have same LayoutRect of legacy.
+  // See http://crbug.com/785687
+  EXPECT_EQ(
+      LayoutNGEnabled() ? LayoutRect(LayoutPoint(745, 0), LayoutSize(65, 13))
+                        : LayoutRect(LayoutPoint(641, 0), LayoutSize(143, 13)),
+      ToLayoutInline(GetLayoutObjectByElementId("rtl2"))->LinesBoundingBox());
+  EXPECT_EQ(LayoutRect(LayoutPoint(0, 0), LayoutSize(26, 39)),
+            ToLayoutInline(GetLayoutObjectByElementId("vertical"))
+                ->LinesBoundingBox());
+}
+
 TEST_F(LayoutInlineTest, SimpleContinuation) {
   SetBodyInnerHTML(
       "<span id='splitInline'><i id='before'></i><h1 id='blockChild'></h1><i "