[layoutng] Preallocate some space in the layout opportunities vector

The number 8 for the initial capacity was picked at random.

This seems to help especially with the float perf tests.

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: Ie4217a459848e7269c791cf864f9aab163d7895d
Reviewed-on: https://chromium-review.googlesource.com/1216813Reviewed-by: Emil A Eklund <eae@chromium.org>
Commit-Queue: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#590095}

third_party/blink/renderer/core/layout/ng/exclusions/ng_exclusion_space.cc

@@ -476,7 +476,7 @@ NGLayoutOpportunity NGExclusionSpace::DerivedGeometry::FindLayoutOpportunity(
   // TODO(ikilpatrick): Determine what to do for a -ve available_inline_size.
   // TODO(ikilpatrick): Change this so that it iterates over the
   // shelves/opportunities instead for querying for all of them.
-  Vector<NGLayoutOpportunity> opportunities =
+  LayoutOpportunityVector opportunities =
       AllLayoutOpportunities(offset, available_inline_size);
 
   for (const auto& opportunity : opportunities) {
@@ -495,11 +495,11 @@ NGLayoutOpportunity NGExclusionSpace::DerivedGeometry::FindLayoutOpportunity(
   return NGLayoutOpportunity();
 }
 
-Vector<NGLayoutOpportunity>
+LayoutOpportunityVector
 NGExclusionSpace::DerivedGeometry::AllLayoutOpportunities(
     const NGBfcOffset& offset,
     const LayoutUnit available_inline_size) const {
-  Vector<NGLayoutOpportunity> opportunities;
+  LayoutOpportunityVector opportunities;
 
   auto* shelves_it = shelves_.begin();
   auto* opps_it = opportunities_.begin();

third_party/blink/renderer/core/layout/ng/exclusions/ng_exclusion_space.h

@@ -17,6 +17,8 @@
 
 namespace blink {
 
+typedef Vector<NGLayoutOpportunity, 8> LayoutOpportunityVector;
+
 // The exclusion space represents all of the exclusions within a block
 // formatting context.
 //
@@ -53,7 +55,7 @@ class CORE_EXPORT NGExclusionSpace {
         offset, available_inline_size, minimum_size);
   }
 
-  Vector<NGLayoutOpportunity> AllLayoutOpportunities(
+  LayoutOpportunityVector AllLayoutOpportunities(
       const NGBfcOffset& offset,
       const LayoutUnit available_inline_size) const {
     // If the area clears all floats, we can just return a single layout
@@ -62,7 +64,7 @@ class CORE_EXPORT NGExclusionSpace {
       NGBfcOffset end_offset(
           offset.line_offset + available_inline_size.ClampNegativeToZero(),
           LayoutUnit::Max());
-      return Vector<NGLayoutOpportunity>(
+      return LayoutOpportunityVector(
           {NGLayoutOpportunity(NGBfcRect(offset, end_offset), nullptr)});
     }
 
@@ -198,7 +200,7 @@ class CORE_EXPORT NGExclusionSpace {
         const LayoutUnit available_inline_size,
         const NGLogicalSize& minimum_size) const;
 
-    Vector<NGLayoutOpportunity> AllLayoutOpportunities(
+    LayoutOpportunityVector AllLayoutOpportunities(
         const NGBfcOffset& offset,
         const LayoutUnit available_inline_size) const;
 

third_party/blink/renderer/core/layout/ng/exclusions/ng_exclusion_space_test.cc

@@ -19,10 +19,9 @@ namespace {
 TEST(NGExclusionSpaceTest, Empty) {
   NGExclusionSpace exclusion_space;
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(100));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(100));
 
   EXPECT_EQ(1u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(), LayoutUnit()),
@@ -55,10 +54,9 @@ TEST(NGExclusionSpaceTest, SingleExclusion) {
                 NGBfcOffset(LayoutUnit(60), LayoutUnit(90))),
       EFloat::kLeft));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(100));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(100));
 
   EXPECT_EQ(3u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(), LayoutUnit()),
@@ -124,10 +122,9 @@ TEST(NGExclusionSpaceTest, TwoExclusions) {
                 NGBfcOffset(LayoutUnit(400), LayoutUnit(150))),
       EFloat::kRight));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(400));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(400));
 
   EXPECT_EQ(4u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(150), LayoutUnit()),
@@ -175,10 +172,9 @@ TEST(NGExclusionSpaceTest, SolidEdges) {
                 NGBfcOffset(LayoutUnit(70), LayoutUnit(35))),
       EFloat::kRight));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(80));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(80));
 
   EXPECT_EQ(5u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(20), LayoutUnit()),
@@ -223,10 +219,9 @@ TEST(NGExclusionSpaceTest, OverlappingWithShelf) {
                 NGBfcOffset(LayoutUnit(90), LayoutUnit(35))),
       EFloat::kRight));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(80));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(80));
 
   EXPECT_EQ(4u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(20), LayoutUnit()),
@@ -271,10 +266,9 @@ TEST(NGExclusionSpaceTest, InsertBetweenShelves) {
                 NGBfcOffset(LayoutUnit(30), LayoutUnit(25))),
       EFloat::kLeft));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(30), LayoutUnit(15)},
-          /* available_size */ LayoutUnit(30));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(30), LayoutUnit(15)},
+      /* available_size */ LayoutUnit(30));
 
   // NOTE: This demonstrates a quirk when querying the exclusion space for
   // opportunities. The exclusion space may return multiple exclusions of
@@ -298,10 +292,9 @@ TEST(NGExclusionSpaceTest, ZeroInlineSizeOpportunity) {
                 NGBfcOffset(LayoutUnit(100), LayoutUnit(10))),
       EFloat::kLeft));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(100));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(100));
 
   EXPECT_EQ(2u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(100), LayoutUnit()),
@@ -318,10 +311,9 @@ TEST(NGExclusionSpaceTest, NegativeInlineSizeOpportunityLeft) {
                 NGBfcOffset(LayoutUnit(120), LayoutUnit(10))),
       EFloat::kLeft));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(100));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(100));
 
   EXPECT_EQ(2u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(120), LayoutUnit()),
@@ -338,10 +330,9 @@ TEST(NGExclusionSpaceTest, NegativeInlineSizeOpportunityRight) {
                 NGBfcOffset(LayoutUnit(100), LayoutUnit(10))),
       EFloat::kRight));
 
-  Vector<NGLayoutOpportunity> opportunites =
-      exclusion_space.AllLayoutOpportunities(
-          /* offset */ {LayoutUnit(), LayoutUnit()},
-          /* available_size */ LayoutUnit(100));
+  LayoutOpportunityVector opportunites = exclusion_space.AllLayoutOpportunities(
+      /* offset */ {LayoutUnit(), LayoutUnit()},
+      /* available_size */ LayoutUnit(100));
 
   EXPECT_EQ(2u, opportunites.size());
   TEST_OPPORTUNITY(opportunites[0], NGBfcOffset(LayoutUnit(), LayoutUnit()),

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

@@ -654,7 +654,7 @@ scoped_refptr<NGLayoutResult> NGInlineLayoutAlgorithm::Layout() {
 
   // We query all the layout opportunities on the initial exclusion space up
   // front, as if the line breaker may add floats and change the opportunities.
-  const Vector<NGLayoutOpportunity> opportunities =
+  const LayoutOpportunityVector opportunities =
       initial_exclusion_space->AllLayoutOpportunities(
           ConstraintSpace().BfcOffset(),
           ConstraintSpace().AvailableSize().inline_size);

third_party/blink/renderer/core/layout/ng/ng_block_layout_algorithm.cc

@@ -972,7 +972,7 @@ NGBlockLayoutAlgorithm::LayoutNewFormattingContext(
       (child_available_size_.inline_size - inline_margin.ClampNegativeToZero())
           .ClampNegativeToZero();
 
-  Vector<NGLayoutOpportunity> opportunities =
+  LayoutOpportunityVector opportunities =
       exclusion_space_->AllLayoutOpportunities(origin_offset, inline_size);
 
   // We should always have at least one opportunity.