Initial implementation of LayoutNG's block layout algorithm for floats.

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
index 131dbb918730e85ec9d65421cd3e883720c14304..7b7904be52113a2524388543339cc93bbe1bcaef 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
@@ -61,7 +61,16 @@ class CORE_EXPORT NGConstraintSpace final
   // NGConstraintSpace or a NGPhysicalConstraintSpace.
   static NGConstraintSpace* CreateFromLayoutObject(const LayoutBox&);
 
-  NGPhysicalConstraintSpace* PhysicalSpace() const { return physical_space_; }
+  // Mutable Getters.
+  // TODO(layout-dev): remove const constraint from MutablePhysicalSpace method
+  NGPhysicalConstraintSpace* MutablePhysicalSpace() const {
+    return physical_space_;
+  }
+
+  // Read-only Getters.
+  const NGPhysicalConstraintSpace* PhysicalSpace() const {
+    return physical_space_;
+  }
 
   NGDirection Direction() const { return static_cast<NGDirection>(direction_); }
 
@@ -69,6 +78,11 @@ class CORE_EXPORT NGConstraintSpace final
     return static_cast<NGWritingMode>(writing_mode_);
   }
 
+  // Adds the exclusion in the physical constraint space.
+  // Passing the exclusion ignoring the writing mode is fine here since the
+  // exclusion is set in physical coordinates.
+  void AddExclusion(const NGExclusion* exclusion) const;
+
   // Size of the container. Used for the following three cases:
   // 1) Percentage resolution.
   // 2) Resolving absolute positions of children.