Shrink canonicalizedTitle a bit.

Noticed that it was (in content_shell x64 for Linux) 421 and 425 bytes
which seemed excessive. Just rewrote it a bit to do less work for the
same result.

gcc (not even going to guess why createQualifiedName changed):
---------------------------------------------------------------------------------------------------------------------
 -635 - Source: /home/bratell/src/chromium/src/third_party/WebKit/Source/core/dom/Document.cpp - (gained 8, lost 643)
---------------------------------------------------------------------------------------------------------------------
  Grown symbols:
         +8: WebCore::Document::didChangeVisibilityState() type=t, (was 299 bytes, now 307 bytes)
  Shrunk symbols:
        -64: WebCore::createQualifiedName(WTF::AtomicString const&, WTF::AtomicString const&, WebCore::ExceptionState&) type=t, (was 1112 bytes, now 1048 bytes)
       -579: WebCore::Document::updateTitle(WTF::String const&) type=t, (was 1541 bytes, now 962 bytes)

clang:
  Shrunk symbols:
       -241: WebCore::Document::updateTitle(WTF::String const&) type=t, (was 1124 bytes, now 883 bytes)

Review URL: https://codereview.chromium.org/390003003

git-svn-id: svn://svn.chromium.org/blink/trunk@181746 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/Document.cpp

@@ -1320,49 +1320,28 @@ PassRefPtrWillBeRawPtr<Range> Document::caretRangeFromPoint(int x, int y)
 template <typename CharacterType>
 static inline String canonicalizedTitle(Document* document, const String& title)
 {
-    const CharacterType* characters = title.getCharacters<CharacterType>();
     unsigned length = title.length();
-    unsigned i;
-
-    StringBuffer<CharacterType> buffer(length);
     unsigned builderIndex = 0;
+    const CharacterType* characters = title.getCharacters<CharacterType>();
 
-    // Skip leading spaces and leading characters that would convert to spaces
-    for (i = 0; i < length; ++i) {
-        CharacterType c = characters[i];
-        if (!(c <= 0x20 || c == 0x7F))
-            break;
-    }
-
-    if (i == length)
-        return String();
+    StringBuffer<CharacterType> buffer(length);
 
-    // Replace control characters with spaces, and backslashes with currency symbols, and collapse whitespace.
-    bool previousCharWasWS = false;
-    for (; i < length; ++i) {
-        CharacterType c = characters[i];
+    // Replace control characters with spaces and collapse whitespace.
+    bool pendingWhitespace = false;
+    for (unsigned i = 0; i < length; ++i) {
+        UChar32 c = characters[i];
         if (c <= 0x20 || c == 0x7F || (WTF::Unicode::category(c) & (WTF::Unicode::Separator_Line | WTF::Unicode::Separator_Paragraph))) {
-            if (previousCharWasWS)
-                continue;
-            buffer[builderIndex++] = ' ';
-            previousCharWasWS = true;
+            if (builderIndex != 0)
+                pendingWhitespace = true;
         } else {
+            if (pendingWhitespace) {
+                buffer[builderIndex++] = ' ';
+                pendingWhitespace = false;
+            }
             buffer[builderIndex++] = c;
-            previousCharWasWS = false;
         }
     }
-
-    // Strip trailing spaces
-    while (builderIndex > 0) {
-        --builderIndex;
-        if (buffer[builderIndex] != ' ')
-            break;
-    }
-
-    if (!builderIndex && buffer[builderIndex] == ' ')
-        return String();
-
-    buffer.shrink(builderIndex + 1);
+    buffer.shrink(builderIndex);
 
     return String::adopt(buffer);
 }

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

@@ -52,19 +52,6 @@ public:
     }
 
     void shrink(unsigned newLength);
-    void resize(unsigned newLength)
-    {
-        if (!m_data) {
-            CharType* characters;
-            m_data = StringImpl::createUninitialized(newLength, characters);
-            return;
-        }
-        if (newLength > m_data->length()) {
-            m_data = StringImpl::reallocate(m_data.release(), newLength);
-            return;
-        }
-        shrink(newLength);
-    }
 
     unsigned length() const { return m_data ? m_data->length() : 0; }
     CharType* characters() { return length() ? const_cast<CharType*>(m_data->getCharacters<CharType>()) : 0; }