Add StringView constructor that takes a ref to save a branch in CSSTokenizerInputStream::rangeAt

third_party/WebKit/Source/wtf/text/StringView.h

 // Copyright 2016 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.
 
 #ifndef WTF_StringView_h
 #define WTF_StringView_h
 
 #include "wtf/Allocator.h"
 #include "wtf/GetPtr.h"
 #if DCHECK_IS_ON()
@@ skipping 25 matching lines @@
     // From a StringView:
     StringView(const StringView&, unsigned offset, unsigned length);
     StringView(const StringView& view, unsigned offset)
         : StringView(view, offset, view.m_length - offset) {}
 
     // From a StringImpl:
     StringView(StringImpl*);
     StringView(StringImpl*, unsigned offset);
     StringView(StringImpl*, unsigned offset, unsigned length);
 
+    // From a non-null StringImpl, avoids the null check.
+    StringView(StringImpl& impl)
+        : m_impl(&impl)
+        , m_bytes(impl.bytes())
+        , m_length(impl.length()) {}
+    StringView(StringImpl&, unsigned offset);
+    StringView(StringImpl&, unsigned offset, unsigned length);
+
     // From an String, implemented in String.h
     inline StringView(const String&, unsigned offset, unsigned length);
     inline StringView(const String&, unsigned offset);
     inline StringView(const String&);
 
     // From an AtomicString, implemented in AtomicString.h
     inline StringView(const AtomicString&, unsigned offset, unsigned length);
     inline StringView(const AtomicString&, unsigned offset);
     inline StringView(const AtomicString&);
 
@@ skipping 112 matching lines @@
 inline StringView::StringView(StringImpl* impl, unsigned offset)
 {
     impl ? set(*impl, offset, impl->length() - offset) : clear();
 }
 
 inline StringView::StringView(StringImpl* impl, unsigned offset, unsigned length)
 {
     impl ? set(*impl, offset, length) : clear();
 }
 
+inline StringView::StringView(StringImpl& impl, unsigned offset)
+{
+    set(impl, offset, impl.length() - offset);
+}
+
+inline StringView::StringView(StringImpl& impl, unsigned offset, unsigned length)
+{
+    set(impl, offset, length);
+}
+
 inline void StringView::clear()
 {
     m_length = 0;
     m_bytes = nullptr;
     m_impl = StringImpl::empty(); // mark as 8 bit.
 }
 
 inline void StringView::set(StringImpl& impl, unsigned offset, unsigned length)
 {
     SECURITY_DCHECK(offset + length <= impl.length());
@@ skipping 20 matching lines @@
 inline bool operator!=(const StringView& a, const StringView& b)
 {
     return !(a == b);
 }
 
 } // namespace WTF
 
 using WTF::StringView;
 
 #endif