[LayoutNG] Fix line width when trailing space at block end has kerning

ShapingLineBreaker handles trailing spaces at the end of
wrapped lines. But when the line ends with hard break or at
the end of a block, NGLineBreaker needs to remove the
trailing spaces.

When the trailing space is not safe-to-break; e.g., the font
has kerning pairs between the last non-space character and
the trailing spaces, this patch ensures that the line width
is correct by reshaping the end.

Not doing so caused min-content and max-content differ when
there are no break opportunities, because trailing spaces for
min-content is handled by ShapingLineBreaker while for max-
content is handled by NGLineBreaker.

Bug: 636993
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: If8c810b7e4cfccfd7a35f6dd48d15ce67b98c036
Reviewed-on: https://chromium-review.googlesource.com/1111749
Commit-Queue: Emil A Eklund <eae@chromium.org>
Reviewed-by: Emil A Eklund <eae@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570061}

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t0805-c5512-brdr-rw-00-b-expected.txt

-layer at (0,0) size 800x600
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 800x178
-  LayoutNGBlockFlow {HTML} at (0,0) size 800x178
-    LayoutNGBlockFlow {BODY} at (8,16) size 784x146
-      LayoutNGBlockFlow {P} at (0,0) size 784x20
-        LayoutText {#text} at (0,0) size 448x19
-          text run at (0,0) width 448: "The three boxes below should have progressively thinner right borders."
-      LayoutNGBlockFlow {P} at (0,36) size 784x26 [border: (3px solid #000000) (5px solid #000000) (3px solid #000000)]
-        LayoutText {#text} at (3,3) size 11x19
-          text run at (3,3) width 11: "A"
-      LayoutNGBlockFlow {P} at (0,78) size 784x26 [border: (3px solid #000000)]
-        LayoutText {#text} at (3,3) size 11x19
-          text run at (3,3) width 11: "B"
-      LayoutNGBlockFlow {P} at (0,120) size 784x26 [border: (3px solid #000000) (1px solid #000000) (3px solid #000000)]
-        LayoutText {#text} at (3,3) size 11x19
-          text run at (3,3) width 11: "C"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t0805-c5514-brdr-lw-00-b-expected.txt

-layer at (0,0) size 800x600
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 800x178
-  LayoutNGBlockFlow {HTML} at (0,0) size 800x178
-    LayoutNGBlockFlow {BODY} at (8,16) size 784x146
-      LayoutNGBlockFlow {P} at (0,0) size 784x20
-        LayoutText {#text} at (0,0) size 439x19
-          text run at (0,0) width 439: "The three boxes below should have progressively thinner left borders."
-      LayoutNGBlockFlow {P} at (0,36) size 784x26 [border: (3px solid #000000) (5px solid #000000)]
-        LayoutText {#text} at (5,3) size 11x19
-          text run at (5,3) width 11: "A"
-      LayoutNGBlockFlow {P} at (0,78) size 784x26 [border: (3px solid #000000)]
-        LayoutText {#text} at (3,3) size 11x19
-          text run at (3,3) width 11: "B"
-      LayoutNGBlockFlow {P} at (0,120) size 784x26 [border: (3px solid #000000) (1px solid #000000)]
-        LayoutText {#text} at (1,3) size 11x19
-          text run at (1,3) width 11: "C"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t0805-c5515-brdr-w-00-a-expected.txt

-layer at (0,0) size 800x600
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 800x178
-  LayoutNGBlockFlow {HTML} at (0,0) size 800x178
-    LayoutNGBlockFlow {BODY} at (8,16) size 784x146
-      LayoutNGBlockFlow {P} at (0,0) size 784x20
-        LayoutText {#text} at (0,0) size 415x19
-          text run at (0,0) width 415: "The three boxes below should have progressively thinner borders."
-      LayoutNGBlockFlow {P} at (0,36) size 784x30 [border: (5px solid #000000)]
-        LayoutText {#text} at (5,5) size 11x19
-          text run at (5,5) width 11: "A"
-      LayoutNGBlockFlow {P} at (0,82) size 784x26 [border: (3px solid #000000)]
-        LayoutText {#text} at (3,3) size 11x19
-          text run at (3,3) width 11: "B"
-      LayoutNGBlockFlow {P} at (0,124) size 784x22 [border: (1px solid #000000)]
-        LayoutText {#text} at (1,1) size 11x19
-          text run at (1,1) width 11: "C"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t0905-c5525-fltcont-00-d-g-expected.txt

@@ -29,5 +29,5 @@ layer at (0,0) size 800x288
               text run at (0,200) width 588: "FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL"
               text run at (0,220) width 588: "FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL"
               text run at (0,240) width 588: "FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL FAIL"
-              text run at (0,260) width 148: "FAIL FAIL FAIL FAIL"
+              text run at (0,260) width 149: "FAIL FAIL FAIL FAIL"
           LayoutText {#text} at (0,0) size 0x0

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t1202-counter-13-b-expected.txt

@@ -79,5 +79,5 @@ layer at (0,0) size 800x100
               text run at (155,0) width 9: "L"
         LayoutText {#text} at (0,0) size 0x0
       LayoutNGBlockFlow {DIV} at (0,56) size 784x20
-        LayoutText {#text} at (0,0) size 164x19
-          text run at (0,0) width 164: "A B C D E F G H I J K L"
+        LayoutText {#text} at (0,0) size 165x19
+          text run at (0,0) width 165: "A B C D E F G H I J K L"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t1202-counter-14-b-expected.txt

@@ -79,5 +79,5 @@ layer at (0,0) size 800x100
               text run at (155,0) width 9: "L"
         LayoutText {#text} at (0,0) size 0x0
       LayoutNGBlockFlow {DIV} at (0,56) size 784x20
-        LayoutText {#text} at (0,0) size 164x19
-          text run at (0,0) width 164: "A B C D E F G H I J K L"
+        LayoutText {#text} at (0,0) size 165x19
+          text run at (0,0) width 165: "A B C D E F G H I J K L"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t1202-counters-13-b-expected.txt

@@ -79,5 +79,5 @@ layer at (0,0) size 800x100
               text run at (320,0) width 25: "A.L"
         LayoutText {#text} at (0,0) size 0x0
       LayoutNGBlockFlow {DIV} at (0,56) size 784x20
-        LayoutText {#text} at (0,0) size 345x19
-          text run at (0,0) width 345: "A.A A.B A.C A.D A.E A.F A.G A.H A.I A.J A.K A.L"
+        LayoutText {#text} at (0,0) size 346x19
+          text run at (0,0) width 346: "A.A A.B A.C A.D A.E A.F A.G A.H A.I A.J A.K A.L"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/css2.1/t1202-counters-14-b-expected.txt

@@ -79,5 +79,5 @@ layer at (0,0) size 800x100
               text run at (320,0) width 25: "A.L"
         LayoutText {#text} at (0,0) size 0x0
       LayoutNGBlockFlow {DIV} at (0,56) size 784x20
-        LayoutText {#text} at (0,0) size 345x19
-          text run at (0,0) width 345: "A.A A.B A.C A.D A.E A.F A.G A.H A.I A.J A.K A.L"
+        LayoutText {#text} at (0,0) size 346x19
+          text run at (0,0) width 346: "A.A A.B A.C A.D A.E A.F A.G A.H A.I A.J A.K A.L"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/fast/css-generated-content/012-expected.txt

@@ -4,8 +4,8 @@ layer at (0,0) size 800x600
   LayoutNGBlockFlow {HTML} at (0,0) size 800x600
     LayoutNGBlockFlow {BODY} at (8,8) size 784x568
       LayoutNGBlockFlow {H1} at (0,0) size 784x57
-        LayoutText {#text} at (0,1) size 772x55
-          text run at (0,1) width 772: "Inheritance bug for floated first-letter"
+        LayoutText {#text} at (0,1) size 773x55
+          text run at (0,1) width 773: "Inheritance bug for floated first-letter"
       LayoutNGBlockFlow {P} at (0,89.16) size 784x172 [bgcolor=#EEEEEE] [border: (1px solid #000000)]
         LayoutInline {<pseudo:first-letter>} at (0,0) size 54x86 [color=#008000] [border: (1px dashed #008000)]
           LayoutTextFragment (anonymous) at (2,2) size 52x84

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/fast/css/nth-child-dynamic-expected.txt

@@ -18,14 +18,14 @@ layer at (0,0) size 800x600
           LayoutText {#text} at (0,0) size 29x19
             text run at (0,0) width 29: "DIV"
         LayoutNGBlockFlow {P} at (11,46) size 747x20
-          LayoutText {#text} at (0,0) size 8x19
-            text run at (0,0) width 8: "P"
+          LayoutText {#text} at (0,0) size 9x19
+            text run at (0,0) width 9: "P"
         LayoutNGBlockFlow {DIV} at (6,66) size 752x20 [color=#FF0000] [bgcolor=#9999FF]
           LayoutText {#text} at (0,0) size 131x19
             text run at (0,0) width 131: "DIV red text blue bg"
         LayoutNGBlockFlow {P} at (11,86) size 747x20
-          LayoutText {#text} at (0,0) size 8x19
-            text run at (0,0) width 8: "P"
+          LayoutText {#text} at (0,0) size 9x19
+            text run at (0,0) width 9: "P"
         LayoutNGBlockFlow {DIV} at (6,106) size 752x20
           LayoutText {#text} at (0,0) size 29x19
             text run at (0,0) width 29: "DIV"
@@ -36,14 +36,14 @@ layer at (0,0) size 800x600
           LayoutText {#text} at (0,0) size 29x19
             text run at (0,0) width 29: "DIV"
         LayoutNGBlockFlow {P} at (11,166) size 747x20
-          LayoutText {#text} at (0,0) size 8x19
-            text run at (0,0) width 8: "P"
+          LayoutText {#text} at (0,0) size 9x19
+            text run at (0,0) width 9: "P"
         LayoutNGBlockFlow {DIV} at (6,186) size 752x20 [color=#FF0000]
           LayoutText {#text} at (0,0) size 80x19
             text run at (0,0) width 80: "DIV red text"
         LayoutNGBlockFlow {P} at (11,206) size 747x20
-          LayoutText {#text} at (0,0) size 8x19
-            text run at (0,0) width 8: "P"
+          LayoutText {#text} at (0,0) size 9x19
+            text run at (0,0) width 9: "P"
       LayoutNGBlockFlow {DIV} at (10,314) size 764x252 [border: (1px solid #000000)]
         LayoutText {#text} at (6,6) size 261x19
           text run at (6,6) width 261: "child 0: PASS: found color rgb(255, 0, 0)"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/fast/css/visibility-hit-test-expected.txt

@@ -7,5 +7,5 @@ layer at (0,0) size 800x600
         LayoutImage {IMG} at (0,0) size 300x300
       LayoutText {#text} at (300,285) size 4x19
         text run at (300,285) width 4: " "
-      LayoutText {#text} at (304,285) size 442x19
-        text run at (304,285) width 442: "The element at position (100, 100) should be the body. Result: BODY"
+      LayoutText {#text} at (304,285) size 443x19
+        text run at (304,285) width 443: "The element at position (100, 100) should be the body. Result: BODY"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/paint/markers/inline-spelling-markers-hidpi-composited-expected.txt

@@ -7,8 +7,8 @@ layer at (0,0) size 1600x356
         LayoutText {#text} at (0,0) size 58x36
           text run at (0,0) width 58: "LTR"
       LayoutNGBlockFlow (anonymous) at (0,81) size 1568x37
-        LayoutText {#text} at (0,0) size 58x36
-          text run at (0,0) width 58: "RTL"
+        LayoutText {#text} at (0,0) size 59x36
+          text run at (0,0) width 59: "RTL"
       LayoutNGBlockFlow (anonymous) at (0,162) size 1568x37
         LayoutText {#text} at (0,0) size 367x36
           text run at (0,0) width 367: "LTR (text-overflow:ellipses)"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/paint/markers/inline-spelling-markers-hidpi-expected.txt

@@ -7,8 +7,8 @@ layer at (0,0) size 1600x356
         LayoutText {#text} at (0,0) size 58x36
           text run at (0,0) width 58: "LTR"
       LayoutNGBlockFlow (anonymous) at (0,81) size 1568x37
-        LayoutText {#text} at (0,0) size 58x36
-          text run at (0,0) width 58: "RTL"
+        LayoutText {#text} at (0,0) size 59x36
+          text run at (0,0) width 59: "RTL"
       LayoutNGBlockFlow (anonymous) at (0,162) size 1568x37
         LayoutText {#text} at (0,0) size 367x36
           text run at (0,0) width 367: "LTR (text-overflow:ellipses)"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/paint/markers/inline_spelling_markers-expected.txt

@@ -7,8 +7,8 @@ layer at (0,0) size 800x184
         LayoutText {#text} at (0,0) size 30x19
           text run at (0,0) width 30: "LTR"
       LayoutNGBlockFlow (anonymous) at (0,42) size 784x20
-        LayoutText {#text} at (0,0) size 29x19
-          text run at (0,0) width 29: "RTL"
+        LayoutText {#text} at (0,0) size 30x19
+          text run at (0,0) width 30: "RTL"
       LayoutNGBlockFlow (anonymous) at (0,84) size 784x20
         LayoutText {#text} at (0,0) size 183x19
           text run at (0,0) width 183: "LTR (text-overflow:ellipses):"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/svg/hixie/mixed/008-expected.txt

-layer at (0,0) size 800x600
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 800x465
-  LayoutNGBlockFlow {html} at (0,0) size 800x465
-    LayoutNGBlockFlow {body} at (8,16) size 784x441
-      LayoutNGBlockFlow {p} at (0,0) size 784x20 [color=#000080]
-        LayoutText {#text} at (0,0) size 405x19
-          text run at (0,0) width 405: "There should be a blue circle with the word \"TEST\" in it below."
-      LayoutNGBlockFlow (anonymous) at (0,36) size 784x405
-        LayoutSVGRoot {svg} at (0,0) size 400x400
-          LayoutSVGRect {rect} at (0,0) size 400x400 [fill={[type=SOLID] [color=#0000FF]}] [x=0.00] [y=0.00] [width=400.00] [height=400.00]
-          LayoutSVGEllipse {circle} at (0,0) size 400x400 [fill={[type=SOLID] [color=#000080]}] [cx=200.00] [cy=200.00] [r=200.00]
-          LayoutSVGForeignObject {foreignObject} at (0,175) size 400x50 [color=#FFFFFF]
-            LayoutNGBlockFlow {div} at (0,0) size 400x59
-              LayoutText {#text} at (140,1) size 120x57
-                text run at (140,1) width 120: "TEST"
-        LayoutText {#text} at (0,0) size 0x0
-layer at (8,227) size 400x50 scrollHeight 59
-  LayoutSVGForeignObject {foreignObject} at (0,175) size 400x50 [color=#FFFFFF]
-    LayoutNGBlockFlow {div} at (0,0) size 400x59
-      LayoutText {#text} at (140,1) size 120x57
-        text run at (140,1) width 120: "TEST"

third_party/WebKit/LayoutTests/flag-specific/enable-blink-features=LayoutNG/svg/zoom/page/zoom-hixie-mixed-008-expected.txt

-layer at (0,0) size 800x600 clip at (0,0) size 785x600 scrollHeight 668
-  LayoutView at (0,0) size 800x600
-layer at (0,0) size 785x668 backgroundClip at (0,0) size 785x600 clip at (0,0) size 785x600
-  LayoutNGBlockFlow {html} at (0,0) size 785x667.58
-    LayoutNGBlockFlow {body} at (11.52,23.03) size 761.97x633.03
-      LayoutNGBlockFlow {p} at (0,0) size 761.97x27 [color=#000080]
-        LayoutText {#text} at (0,0) size 594x26
-          text run at (0,0) width 594: "There should be a blue circle with the word \"TEST\" in it below."
-      LayoutNGBlockFlow (anonymous) at (0,50.03) size 761.97x583
-        LayoutSVGRoot {svg} at (0,0) size 576x576
-          LayoutSVGRect {rect} at (0,0) size 400x400 [fill={[type=SOLID] [color=#0000FF]}] [x=0.00] [y=0.00] [width=400.00] [height=400.00]
-          LayoutSVGEllipse {circle} at (0,0) size 400x400 [fill={[type=SOLID] [color=#000080]}] [cx=200.00] [cy=200.00] [r=200.00]
-          LayoutSVGForeignObject {foreignObject} at (0,175) size 400x50 [color=#FFFFFF]
-            LayoutNGBlockFlow {div} at (0,0) size 400x59
-              LayoutText {#text} at (140,1) size 120x57
-                text run at (140,1) width 120: "TEST"
-        LayoutText {#text} at (0,0) size 0x0
-layer at (12,248) size 400x50 backgroundClip at (12,325) size 576x72 clip at (0,0) size 0x0 scrollHeight 59
-  LayoutSVGForeignObject {foreignObject} at (0,175) size 400x50 [color=#FFFFFF]
-    LayoutNGBlockFlow {div} at (0,0) size 400x59
-      LayoutText {#text} at (140,1) size 120x57
-        text run at (140,1) width 120: "TEST"

third_party/WebKit/LayoutTests/platform/linux/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-expected.txt

@@ -147,7 +147,7 @@ layer at (0,0) size 1046x2264 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2094) size 138x54
           LayoutTableRow {TR} at (0,0) size 138x52
             LayoutNGTableCell {TH} at (2,0) size 134x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (6.50,6) size 30x30
+              LayoutSVGRoot {svg} at (6,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (36,8) size 92x35
                 text run at (36,8) width 92: " Footer"

third_party/WebKit/LayoutTests/platform/linux/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-extra-pages-expected.txt

@@ -148,7 +148,7 @@ layer at (0,0) size 1046x4376 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2206) size 138x54
           LayoutTableRow {TR} at (0,0) size 138x52
             LayoutNGTableCell {TH} at (2,0) size 134x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (6.50,6) size 30x30
+              LayoutSVGRoot {svg} at (6,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (36,8) size 92x35
                 text run at (36,8) width 92: " Footer"

third_party/WebKit/LayoutTests/platform/mac/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-expected.txt

@@ -147,7 +147,7 @@ layer at (0,0) size 1046x2264 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2094) size 139x54
           LayoutTableRow {TR} at (0,0) size 139x52
             LayoutNGTableCell {TH} at (2,0) size 135x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (6.53,6) size 30x30
+              LayoutSVGRoot {svg} at (6.27,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (36,8) size 93x36
                 text run at (36,8) width 93: " Footer"

third_party/WebKit/LayoutTests/platform/mac/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-extra-pages-expected.txt

@@ -148,7 +148,7 @@ layer at (0,0) size 1046x4376 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2206) size 139x54
           LayoutTableRow {TR} at (0,0) size 139x52
             LayoutNGTableCell {TH} at (2,0) size 135x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (6.53,6) size 30x30
+              LayoutSVGRoot {svg} at (6.27,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (36,8) size 93x36
                 text run at (36,8) width 93: " Footer"

third_party/WebKit/LayoutTests/platform/win/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-expected.txt

@@ -147,7 +147,7 @@ layer at (0,0) size 1046x2264 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2094) size 136x54
           LayoutTableRow {TR} at (0,0) size 136x52
             LayoutNGTableCell {TH} at (2,0) size 132x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (5.50,6) size 30x30
+              LayoutSVGRoot {svg} at (5,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (35,8) size 92x35
                 text run at (35,8) width 92: " Footer"

third_party/WebKit/LayoutTests/platform/win/virtual/layout_ng_experimental/printing/thead-tfoot-containing-svg-repeat-extra-pages-expected.txt

@@ -148,7 +148,7 @@ layer at (0,0) size 1046x4376 backgroundClip at (0,0) size 800x600 clip at (0,0)
         LayoutTableSection {TFOOT} at (0,2206) size 136x54
           LayoutTableRow {TR} at (0,0) size 136x52
             LayoutNGTableCell {TH} at (2,0) size 132x52 [r=0 c=0 rs=1 cs=1]
-              LayoutSVGRoot {svg} at (5.50,6) size 30x30
+              LayoutSVGRoot {svg} at (5,6) size 30x30
                 LayoutSVGEllipse {circle} at (0,0) size 30x30 [fill={[type=SOLID] [color=#FF0000]}] [cx=15.00] [cy=15.00] [r=15.00]
               LayoutText {#text} at (35,8) size 92x35
                 text run at (35,8) width 92: " Footer"

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

@@ -460,6 +460,49 @@ void NGLineBreaker::BreakText(NGInlineItemResult* item_result,
   }
 }
 
+// Re-shape the specified range of |NGInlineItem|.
+scoped_refptr<ShapeResult> NGLineBreaker::ShapeText(const NGInlineItem& item,
+                                                    unsigned start,
+                                                    unsigned end) {
+  RunSegmenter::RunSegmenterRange segment_range =
+      item.CreateRunSegmenterRange();
+  scoped_refptr<ShapeResult> result = shaper_.Shape(
+      &item.Style()->GetFont(), item.TextShapeResult()->Direction(), start, end,
+      &segment_range);
+  if (UNLIKELY(spacing_.HasSpacing()))
+    result->ApplySpacing(spacing_);
+  return result;
+}
+
+// Truncate the end of |ShapeResult|. The |ShapeResult| is supposed to be at the
+// end of the line, and thus this function makes sure the end is safe-to-break.
+void NGLineBreaker::TruncateTextEnd(NGInlineItemResult* item_result) {
+  DCHECK(item_result);
+  DCHECK(item_result->item);
+  DCHECK(item_result->shape_result);
+  const ShapeResult& source_result = *item_result->shape_result;
+  const unsigned start_offset = item_result->start_offset;
+  const unsigned end_offset = item_result->end_offset;
+
+  scoped_refptr<ShapeResult> new_result;
+  unsigned last_safe = source_result.PreviousSafeToBreakOffset(end_offset);
+  DCHECK_LE(last_safe, end_offset);
+  if (last_safe > start_offset)
+    new_result = source_result.SubRange(start_offset, last_safe);
+  if (last_safe < end_offset) {
+    scoped_refptr<ShapeResult> end_result = ShapeText(
+        *item_result->item, std::max(last_safe, start_offset), end_offset);
+    if (new_result)
+      end_result->CopyRange(0, end_offset, new_result.get());
+    else
+      new_result = std::move(end_result);
+  }
+
+  DCHECK(new_result);
+  item_result->shape_result = std::move(new_result);
+  item_result->inline_size = item_result->shape_result->SnappedWidth();
+}
+
 NGLineBreaker::LineBreakState NGLineBreaker::HandleTrailingSpaces(
     const NGInlineItem& item,
     NGLineInfo* line_info) {
@@ -492,9 +535,8 @@ NGLineBreaker::LineBreakState NGLineBreaker::HandleTrailingSpaces(
 
     NGInlineItemResult* item_result = AddItem(item, end, item_results);
     item_result->has_only_trailing_spaces = true;
-    // TODO(kojii): Should reshape if it's not safe to break.
-    item_result->shape_result = item.TextShapeResult()->SubRange(offset_, end);
-    item_result->inline_size = item_result->shape_result->SnappedWidth();
+    item_result->shape_result = item.TextShapeResult();
+    TruncateTextEnd(item_result);
     line_.position += item_result->inline_size;
     item_result->can_break_after =
         end < text.length() && !IsBreakableSpace(text[end]);
@@ -538,10 +580,7 @@ void NGLineBreaker::RemoveTrailingCollapsibleSpace(NGLineInfo* line_info) {
       unsigned index = std::distance(item_results->begin(), &item_result);
       item_results->EraseAt(index);
     } else {
-      // TODO(kojii): Should reshape if it's not safe to break.
-      item_result.shape_result = item_result.shape_result->SubRange(
-          item_result.start_offset, item_result.end_offset);
-      item_result.inline_size = item_result.shape_result->SnappedWidth();
+      TruncateTextEnd(&item_result);
       line_.position += item_result.inline_size;
     }
     return;

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

@@ -138,6 +138,10 @@ class CORE_EXPORT NGLineBreaker {
                  const NGInlineItem&,
                  LayoutUnit available_width,
                  NGLineInfo*);
+  void TruncateTextEnd(NGInlineItemResult*);
+  scoped_refptr<ShapeResult> ShapeText(const NGInlineItem& item,
+                                       unsigned start,
+                                       unsigned end);
   LineBreakState HandleTrailingSpaces(const NGInlineItem&, NGLineInfo*);
   void RemoveTrailingCollapsibleSpace(NGLineInfo*);
   void AppendHyphen(const NGInlineItem& item, NGLineInfo*);