Make LayoutText::absoluteQuadsForRange to consider leading/trailing whitespaces

Source/core/layout/LayoutText.cpp

Index: Source/core/layout/LayoutText.cpp
diff --git a/Source/core/layout/LayoutText.cpp b/Source/core/layout/LayoutText.cpp
index ac36dc083ba35685a1bf8b5d22a0079e180c6ea5..41bbbbe289bc12a8de78ad0f66f28360f73c1f8f 100644
--- a/Source/core/layout/LayoutText.cpp
+++ b/Source/core/layout/LayoutText.cpp
@@ -441,6 +441,14 @@ void LayoutText::absoluteQuadsForRange(Vector<FloatQuad>& quads, unsigned start,
     start = std::min(start, static_cast<unsigned>(INT_MAX));
     end = std::min(end, static_cast<unsigned>(INT_MAX));
 
+    const unsigned caretMinOffset = static_cast<unsigned>(this->caretMinOffset());
+    const unsigned caretMaxOffset = static_cast<unsigned>(this->caretMaxOffset());
+
+    // Narrows |start| and |end| into |caretMinOffset| and |careMaxOffset|
+    // to ignore unrendered leading and trailing whitespaces.
+    start = std::min(std::max(caretMinOffset, start), caretMaxOffset);
+    end = std::min(std::max(caretMinOffset, end), caretMaxOffset);
+
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
         // Note: box->end() returns the index of the last character, not the index past it
         if (start <= box->start() && box->end() < end) {