Don't widen selection paint rect for linebreaks.

third_party/WebKit/Source/core/paint/InlineTextBoxPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/paint/InlineTextBoxPainter.h"
 
 #include "core/editing/CompositionUnderline.h"
 #include "core/editing/Editor.h"
 #include "core/editing/markers/DocumentMarkerController.h"
@@ skipping 470 matching lines @@
     }
 
     LayoutUnit selectionBottom = m_inlineTextBox.root().selectionBottom();
     LayoutUnit selectionTop = m_inlineTextBox.root().selectionTopAdjustedForPrecedingBlock();
 
     int deltaY = roundToInt(m_inlineTextBox.lineLayoutItem().style()->isFlippedLinesWritingMode() ? selectionBottom - m_inlineTextBox.logicalBottom() : m_inlineTextBox.logicalTop() - selectionTop);
     int selHeight = std::max(0, roundToInt(selectionBottom - selectionTop));
 
     FloatPoint localOrigin(boxRect.x().toFloat(), (boxRect.y() - deltaY).toFloat());
     LayoutRect selectionRect = LayoutRect(font.selectionRectForText(textRun, localOrigin, selHeight, sPos, ePos));
-    if (m_inlineTextBox.hasWrappedSelectionNewline())
+    if (m_inlineTextBox.hasWrappedSelectionNewline()
+        // For line breaks, just painting a selection where the line break itself is rendered is sufficient.
+        && !m_inlineTextBox.isLineBreak())
         expandToIncludeNewlineForSelection(selectionRect);
 
     context->fillRect(FloatRect(selectionRect), c);
 }
 
 void InlineTextBoxPainter::expandToIncludeNewlineForSelection(LayoutRect& rect)
 {
     FloatRectOutsets outsets = FloatRectOutsets();
     float spaceWidth = m_inlineTextBox.newlineSpaceWidth();
     if (m_inlineTextBox.isLeftToRightDirection())
@@ skipping 343 matching lines @@
             LayoutPoint textOrigin(boxOrigin.x(), boxOrigin.y() + font.fontMetrics().ascent());
             TextPainter textPainter(pt, font, run, textOrigin, boxRect, m_inlineTextBox.isHorizontal());
 
             textPainter.paint(sPos, ePos, length, textStyle, 0);
         }
     }
 }
 
 
 } // namespace blink