android: Fix crash in blink::LayoutText::localCaretRect()

third_party/WebKit/Source/core/layout/LayoutText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 737 matching lines @@
     if (box->prevLeafChild() && caretOffset == 0)
       caretBox = box->prevLeafChild();
   } else {
     if (box->nextLeafChild() && caretOffset == 0)
       caretBox = box->nextLeafChild();
   }
 
   // Get caret height from a font of character.
   const ComputedStyle* styleToUse =
       caretBox->getLineLayoutItem().style(caretBox->isFirstLineStyle());
+  if (!styleToUse->font().primaryFont())
+    return LayoutRect();
+
   int height = styleToUse->font().primaryFont()->getFontMetrics().height();
   int top = caretBox->logicalTop().toInt();
 
   // Go ahead and round left to snap it to the nearest pixel.
   LayoutUnit left = box->positionForOffset(caretOffset);
 
   // Distribute the caret's width to either side of the offset.
   LayoutUnit caretWidthLeftOfOffset = caretWidth() / 2;
   left -= caretWidthLeftOfOffset;
   LayoutUnit caretWidthRightOfOffset = caretWidth() - caretWidthLeftOfOffset;
@@ skipping 1238 matching lines @@
   LayoutRect rect = LayoutRect(
       IntRect(firstRunX(), firstRunY(), linesBox.width(), linesBox.height()));
   LayoutBlock* block = containingBlock();
   if (block && hasTextBoxes())
     block->adjustChildDebugRect(rect);
 
   return rect;
 }
 
 }  // namespace blink