[LayoutNG] Fix max-content size when floats are outside of content box

This patch fixes max-content size when the line has floats
outside of its content box.

In such case, ComputeContentSize computes a negative value
for |floats_inline_size|. Such |floats_inline_size| should
not affect max-content size.

This patch applies the same fix as r570350 (CL:1113094) to
NGInlineNode.

Bug: 636993
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: I5495e56fb3cf6777a4fd308b61f5eb6e484d03af
Reviewed-on: https://chromium-review.googlesource.com/1138594
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575389}

third_party/WebKit/LayoutTests/FlagExpectations/enable-blink-features=LayoutNG

@@ -532,7 +532,6 @@ crbug.com/591099 fast/css/focus-ring-continuations.html [ Failure ]
 crbug.com/714962 fast/css/focus-ring-recursive-continuations.html [ Failure ]
 crbug.com/714962 fast/css/focus-ring-recursive-inlines.html [ Failure ]
 crbug.com/591099 fast/css/getComputedStyle/computed-style-percentage-top-with-position-inline.html [ Failure ]
-crbug.com/591099 fast/css/negative-text-indent-in-inline-block.html [ Failure ]
 crbug.com/591099 fast/css/outline-narrowLine.html [ Failure ]
 crbug.com/591099 fast/css/transform-inline-style-remove.html [ Failure ]
 crbug.com/591099 fast/css3-text/css3-text-decoration/text-underline-position/text-underline-position-auto.html [ Failure ]

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

@@ -673,6 +673,7 @@ static LayoutUnit ComputeContentSize(NGInlineNode node,
   LayoutUnit result;
   LayoutUnit previous_floats_inline_size =
       input.float_left_inline_size + input.float_right_inline_size;
+  DCHECK_GE(previous_floats_inline_size, 0);
   while (!break_token || !break_token->IsFinished()) {
     unpositioned_floats.clear();
 
@@ -729,7 +730,10 @@ static LayoutUnit ComputeContentSize(NGInlineNode node,
           floats_inline_size = LayoutUnit();
         }
 
-        floats_inline_size += child_sizes.max_size + child_inline_margins;
+        // When negative margins move the float outside the content area,
+        // such float should not affect the content size.
+        floats_inline_size +=
+            (child_sizes.max_size + child_inline_margins).ClampNegativeToZero();
         previous_float_type = float_style.Floating();
       }
     }