Use StringView for startsWith and endsWith.

third_party/WebKit/Source/core/frame/csp/CSPSource.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 "core/frame/csp/CSPSource.h"
 
 #include "core/frame/UseCounter.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "platform/weborigin/KURL.h"
 #include "platform/weborigin/KnownPorts.h"
@@ skipping 35 matching lines @@
 }
 
 bool CSPSource::hostMatches(const KURL& url) const
 {
     const String& host = url.host();
     Document* document = m_policy->document();
     bool match;
 
     bool equalHosts = equalIgnoringCase(host, m_host);
     if (m_hostWildcard == HasWildcard) {
-        match = host.endsWith("." + m_host, TextCaseInsensitive);
+        match = host.endsWith(String("." + m_host), TextCaseInsensitive);

[esprehn, 2016/07/13 23:42:55]

a + b returns a StringAppend, which can't be converted to a StringView. We can
fix this by declaring template<A, B> startsWith(StringAppend<A, B> string) const
{ return startsWith(String(string)); } but I want to save that for another patch
if/when we need it. This is the only place anyone concats a string before
calling these methods today and making the allocation explicit doesn't seem too
bad.

 
         // Chrome used to, incorrectly, match *.x.y to x.y. This was fixed, but
         // the following count measures when a match fails that would have
         // passed the old, incorrect style, in case a lot of sites were
         // relying on that behavior.
         if (document && equalHosts)
             UseCounter::count(*document, UseCounter::CSPSourceWildcardWouldMatchExactHost);
     } else {
         match = equalHosts;
     }
@@ skipping 40 matching lines @@
 {
     return m_host.isEmpty();
 }
 
 DEFINE_TRACE(CSPSource)
 {
     visitor->trace(m_policy);
 }
 
 } // namespace blink