Revert "Make NGOffsetMapping available for non-LayoutNG LayoutBlockFlow"

This reverts commit b43c6fca.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 606292 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtL2I0M2M2ZmNhNDM0OWI3ZjJmZjUzYjQxOTI2ZjVkN2NiNDJlZTRlMGYM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.linux/Cast%20Audio%20Linux/24981

Sample Failed Step: webkit_unit_tests

Original change's description:
> Make NGOffsetMapping available for non-LayoutNG LayoutBlockFlow
> 
> This patch allows computing NGOffsetMapping for legacy inline
> formatting context.
> 
> For an experimental project "Invisible DOM"[1][2] to support
> the find-in-page feature, it is needed to compute the text
> content with whitespace collapsing applied, along with the
> mapping to the DOM offset. This patch adds an API to compute
> NGOffsetMapping even when the LayoutBlockFlow is not laid out
> by LayoutNG for that purpose.
> 
> Note that the project is still in the early phase. We may
> revisit the design as it moves forward.
> 
> [1] https://github.com/rakina/searchable-invisible-dom
> [2] https://www.chromestatus.com/feature/5105291213406208
> 
> Bug: 636993, 873057
> Change-Id: I101b411960813a7b9b5c9c6e2db85d28737af882
> Reviewed-on: https://chromium-review.googlesource.com/c/1322184
> Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
> Reviewed-by: Emil A Eklund <eae@chromium.org>
> Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
> Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
> Commit-Queue: Koji Ishii <kojii@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#606292}

Change-Id: I7942801d9268078959619af61363c3a769fc0a53
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 636993, 873057
Reviewed-on: https://chromium-review.googlesource.com/c/1325350
Cr-Commit-Position: refs/heads/master@{#606316}

third_party/blink/renderer/core/layout/ng/inline/ng_inline_node.cc

@@ -282,69 +282,32 @@ const NGOffsetMapping* NGInlineNode::ComputeOffsetMappingIfNeeded() {
 
   NGInlineNodeData* data = MutableData();
   if (!data->offset_mapping) {
-    DCHECK(!data->text_content.IsNull());
-    ComputeOffsetMapping(GetLayoutBlockFlow(), data);
-    DCHECK(data->offset_mapping);
+    // TODO(xiaochengh): ComputeOffsetMappingIfNeeded() discards the
+    // NGInlineItems and text content built by |builder|, because they are
+    // already there in NGInlineNodeData. For efficiency, we should make
+    // |builder| not construct items and text content.
+    Vector<NGInlineItem> items;
+    items.ReserveCapacity(EstimateInlineItemsCount(*GetLayoutBlockFlow()));
+    NGInlineItemsBuilderForOffsetMapping builder(&items);
+    builder.GetOffsetMappingBuilder().ReserveCapacity(
+        EstimateOffsetMappingItemsCount(*GetLayoutBlockFlow()));
+    const bool update_layout = false;
+    CollectInlinesInternal(GetLayoutBlockFlow(), &builder, nullptr,
+                           update_layout);
+    String text = builder.ToString();
+    DCHECK_EQ(data->text_content, text);
+
+    // TODO(xiaochengh): This doesn't compute offset mapping correctly when
+    // text-transform CSS property changes text length.
+    NGOffsetMappingBuilder& mapping_builder = builder.GetOffsetMappingBuilder();
+    mapping_builder.SetDestinationString(data->text_content);
+    data->offset_mapping =
+        std::make_unique<NGOffsetMapping>(mapping_builder.Build());
   }
 
   return data->offset_mapping.get();
 }
 
-void NGInlineNode::ComputeOffsetMapping(LayoutBlockFlow* layout_block_flow,
-                                        NGInlineNodeData* data) {
-  DCHECK(!data->offset_mapping);
-  DCHECK(!layout_block_flow->GetDocument().NeedsLayoutTreeUpdate());
-
-  // TODO(xiaochengh): ComputeOffsetMappingIfNeeded() discards the
-  // NGInlineItems and text content built by |builder|, because they are
-  // already there in NGInlineNodeData. For efficiency, we should make
-  // |builder| not construct items and text content.
-  Vector<NGInlineItem> items;
-  items.ReserveCapacity(EstimateInlineItemsCount(*layout_block_flow));
-  NGInlineItemsBuilderForOffsetMapping builder(&items);
-  builder.GetOffsetMappingBuilder().ReserveCapacity(
-      EstimateOffsetMappingItemsCount(*layout_block_flow));
-  const bool update_layout = false;
-  CollectInlinesInternal(layout_block_flow, &builder, nullptr, update_layout);
-  if (data->text_content.IsNull())
-    data->text_content = builder.ToString();
-  else
-    DCHECK_EQ(data->text_content, builder.ToString());
-
-  // TODO(xiaochengh): This doesn't compute offset mapping correctly when
-  // text-transform CSS property changes text length.
-  NGOffsetMappingBuilder& mapping_builder = builder.GetOffsetMappingBuilder();
-  mapping_builder.SetDestinationString(data->text_content);
-  data->offset_mapping =
-      std::make_unique<NGOffsetMapping>(mapping_builder.Build());
-  DCHECK(data->offset_mapping);
-}
-
-const NGOffsetMapping* NGInlineNode::GetOffsetMapping(
-    LayoutBlockFlow* layout_block_flow,
-    std::unique_ptr<NGOffsetMapping>* storage) {
-  DCHECK(!layout_block_flow->GetDocument().NeedsLayoutTreeUpdate());
-
-  // If |layout_block_flow| is LayoutNG, compute from |NGInlineNode|.
-  if (layout_block_flow->IsLayoutNGMixin()) {
-    NGInlineNode node(layout_block_flow);
-    if (node.IsPrepareLayoutFinished())
-      return node.ComputeOffsetMappingIfNeeded();
-
-    // When this is not laid out yet, compute each time it is requested.
-    // TODO(kojii): We could still keep the result for later uses but it would
-    // add more states. Reconsider if this turned out to be needed.
-  }
-
-  // If this is not LayoutNG, compute the offset mapping and store in |storage|.
-  // The caller is responsible to keep |storage| for the life cycle.
-  NGInlineNodeData data;
-  ComputeOffsetMapping(layout_block_flow, &data);
-  *storage = std::move(data.offset_mapping);
-  DCHECK(*storage);
-  return storage->get();
-}
-
 // Depth-first-scan of all LayoutInline and LayoutText nodes that make up this
 // NGInlineNode object. Collects LayoutText items, merging them up into the
 // parent LayoutInline where possible, and joining all text content in a single

third_party/blink/renderer/core/layout/ng/inline/ng_inline_node.h

@@ -70,17 +70,6 @@ class CORE_EXPORT NGInlineNode : public NGLayoutInputNode {
   // This funciton must be called with clean layout.
   const NGOffsetMapping* ComputeOffsetMappingIfNeeded();
 
-  // Get |NGOffsetMapping| for the |layout_block_flow|. If |layout_block_flow|
-  // is LayoutNG and it is already laid out, this function is the same as
-  // |ComputeOffsetMappingIfNeeded|. |storage| is not used in this case.
-  //
-  // Otherwise, this function computes |NGOffsetMapping| and store in |storage|
-  // as well as returning the pointer. The caller is responsible for keeping
-  // |storage| for the life cycle of the returned |NGOffsetMapping|.
-  static const NGOffsetMapping* GetOffsetMapping(
-      LayoutBlockFlow* layout_block_flow,
-      std::unique_ptr<NGOffsetMapping>* storage);
-
   bool IsBidiEnabled() const { return Data().is_bidi_enabled_; }
   TextDirection BaseDirection() const { return Data().BaseDirection(); }
 
@@ -132,9 +121,6 @@ class CORE_EXPORT NGInlineNode : public NGLayoutInputNode {
   }
   const NGInlineNodeData& EnsureData();
 
-  static void ComputeOffsetMapping(LayoutBlockFlow* layout_block_flow,
-                                   NGInlineNodeData* data);
-
   friend class NGLineBreakerTest;
   friend class NGInlineNodeLegacy;
 };

third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping_test.cc

@@ -1149,40 +1149,4 @@ TEST_F(NGOffsetMappingTest, TextOverflowEllipsis) {
   TEST_RANGE(mapping.GetRanges(), text, 0u, 1u);
 }
 
-// Test |GetOffsetMapping| which is available both for LayoutNG and for legacy.
-class NGOffsetMappingGetterTest : public RenderingTest,
-                                  public testing::WithParamInterface<bool>,
-                                  private ScopedLayoutNGForTest {
- public:
-  NGOffsetMappingGetterTest() : ScopedLayoutNGForTest(GetParam()) {}
-};
-
-INSTANTIATE_TEST_CASE_P(NGOffsetMappingTest,
-                        NGOffsetMappingGetterTest,
-                        testing::Bool());
-
-TEST_P(NGOffsetMappingGetterTest, Get) {
-  SetBodyInnerHTML(R"HTML(
-    <div id=container>
-      Whitespaces   in this text   should be   collapsed.
-    </div>
-  )HTML");
-  LayoutBlockFlow* layout_block_flow =
-      ToLayoutBlockFlow(GetLayoutObjectByElementId("container"));
-  DCHECK(layout_block_flow->ChildrenInline());
-
-  // For the purpose of this test, ensure this is laid out by each layout
-  // engine.
-  DCHECK_EQ(layout_block_flow->IsLayoutNGMixin(), GetParam());
-
-  std::unique_ptr<NGOffsetMapping> storage;
-  const NGOffsetMapping* mapping =
-      NGInlineNode::GetOffsetMapping(layout_block_flow, &storage);
-  EXPECT_TRUE(mapping);
-  EXPECT_EQ(!storage, GetParam());  // |storage| is used only for legacy.
-
-  const String& text_content = mapping->GetText();
-  EXPECT_EQ(text_content, "Whitespaces in this text should be collapsed.");
-}
-
 }  // namespace blink