Expand WTF::StringView's API to be more like StringPiece.

third_party/WebKit/Source/platform/text/TextRun.h

Index: third_party/WebKit/Source/platform/text/TextRun.h
diff --git a/third_party/WebKit/Source/platform/text/TextRun.h b/third_party/WebKit/Source/platform/text/TextRun.h
index fd194049e0accf6b5d783fc62e546cc0e79fae06..76a5117c44f1bd5648ed82e1a1b1623009dc5eba 100644
--- a/third_party/WebKit/Source/platform/text/TextRun.h
+++ b/third_party/WebKit/Source/platform/text/TextRun.h
@@ -101,33 +101,6 @@ public:
         m_data.characters16 = c;
     }
 
-    TextRun(const String& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false)
-        : m_charactersLength(string.length())
-        , m_len(string.length())
-        , m_xpos(xpos)
-        , m_horizontalGlyphStretch(1)
-        , m_expansion(expansion)
-        , m_expansionBehavior(expansionBehavior)
-        , m_allowTabs(false)
-        , m_direction(direction)
-        , m_directionalOverride(directionalOverride)
-        , m_disableSpacing(false)
-        , m_textJustify(TextJustifyAuto)
-        , m_normalizeSpace(false)
-        , m_tabSize(0)
-    {
-        if (!m_charactersLength) {
-            m_is8Bit = true;
-            m_data.characters8 = 0;
-        } else if (string.is8Bit()) {
-            m_data.characters8 = string.characters8();
-            m_is8Bit = true;
-        } else {
-            m_data.characters16 = string.characters16();
-            m_is8Bit = false;
-        }
-    }
-
     TextRun(const StringView& string, float xpos = 0, float expansion = 0, ExpansionBehavior expansionBehavior = AllowTrailingExpansion | ForbidLeadingExpansion, TextDirection direction = LTR, bool directionalOverride = false)
         : m_charactersLength(string.length())
         , m_len(string.length())