[LayoutNG] Introduces NGPhysicalConstraintSpace and makes NGConstraintSpace a "view".

third_party/WebKit/Source/core/layout/ng/ng_box.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_box.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_box.cc b/third_party/WebKit/Source/core/layout/ng/ng_box.cc
index 65a26654392ee26e54d22e1f6ba6d8fcf159f80b..bc0b5531864cc13d986e3b20048918d4f3d49122 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_box.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_box.cc
@@ -8,21 +8,28 @@
 #include "core/layout/ng/layout_ng_block_flow.h"
 #include "core/layout/ng/ng_block_layout_algorithm.h"
 #include "core/layout/ng/ng_box_iterator.h"
+#include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/layout/ng/ng_fragment_builder.h"
+#include "core/layout/ng/ng_writing_mode.h"
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutBox.h"
 
 namespace blink {
 
-NGFragment* NGBox::layout(const NGConstraintSpace& constraintSpace) {
+NGFragment* NGBox::layout(const NGConstraintSpace* constraintSpace) {
   // We can either use the new layout code to do the layout and then copy the
   // resulting size to the LayoutObject, or use the old layout code and
   // synthesize a fragment.
   NGFragment* fragment = nullptr;
   if (canUseNewLayout()) {
     NGBlockLayoutAlgorithm algorithm(style(), childIterator());
-    fragment = algorithm.layout(constraintSpace);
+
+    // Change the coordinate system of the constraint space.
+    NGConstraintSpace* childConstraintSpace = new NGConstraintSpace(

[cbiesinger, 2016/08/25 22:22:15]

For new code, can we make sure to follow the Google style guide for naming? I.e.
child_constraint_space, FromPlatformWritingMode.

[ikilpatrick, 2016/08/25 23:14:29]

Yup done. Sorry, hopefully wont take that long to change habits :)

+        fromPlatformWritingMode(style()->getWritingMode()), constraintSpace);
+
+    fragment = algorithm.layout(childConstraintSpace);
     m_layoutBox->setLogicalWidth(fragment->InlineSize());
     m_layoutBox->setLogicalHeight(fragment->BlockSize());
     if (m_layoutBox->isLayoutBlock())
@@ -30,7 +37,7 @@ NGFragment* NGBox::layout(const NGConstraintSpace& constraintSpace) {
     m_layoutBox->clearNeedsLayout();
   } else {
     // TODO(layout-ng): If fixedSize is true, set the override width/height too
-    NGLogicalSize containerSize = constraintSpace.ContainerSize();
+    NGLogicalSize containerSize = constraintSpace->ContainerSize();
     m_layoutBox->setOverrideContainingBlockContentLogicalWidth(
         containerSize.inline_size);
     m_layoutBox->setOverrideContainingBlockContentLogicalHeight(