Revert of Fix InlineTextBox::characterWidths() not to measure every substring

third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp

Index: third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp
diff --git a/third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp b/third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp
index a0c1174ccb9df065faea866e7cb808255e31cf6a..1f0885bd07d47f6b58737da6df75919f2e6c22a5 100644
--- a/third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp
+++ b/third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp
@@ -30,7 +30,6 @@
 #include "core/layout/line/AbstractInlineTextBox.h"
 #include "core/layout/line/EllipsisBox.h"
 #include "core/paint/InlineTextBoxPainter.h"
-#include "platform/fonts/CharacterRange.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/fonts/shaping/SimpleShaper.h"
 #include "wtf/Vector.h"
@@ -545,13 +544,15 @@
     const ComputedStyle& styleToUse = getLineLayoutItem().styleRef(isFirstLineStyle());
     const Font& font = styleToUse.font();
 
-    TextRun textRun = constructTextRun(styleToUse, font);
-    Vector<CharacterRange> ranges = font.individualCharacterRanges(textRun);
-    DCHECK_EQ(ranges.size(), m_len);
-
-    widths.resize(ranges.size());
-    for (unsigned i = 0; i < ranges.size(); i++)
-        widths[i] = ranges[i].width();
+    float lastWidth = 0;
+    widths.resize(m_len);
+    for (unsigned i = 0; i < m_len; i++) {
+        StringView substringView = getLineLayoutItem().text().createView();
+        substringView.narrow(start(), 1 + i);
+        TextRun textRun = constructTextRun(styleToUse, font, substringView, m_len);
+        widths[i] = font.width(textRun, nullptr, nullptr) - lastWidth;
+        lastWidth = font.width(textRun, nullptr, nullptr);
+    }
 }
 
 TextRun InlineTextBox::constructTextRun(const ComputedStyle& style, const Font& font, StringBuilder* charactersWithHyphen) const