Revert CompressibleString (and its UMA)

third_party/WebKit/Source/platform/text/CompressibleString.cpp

Index: third_party/WebKit/Source/platform/text/CompressibleString.cpp
diff --git a/third_party/WebKit/Source/platform/text/CompressibleString.cpp b/third_party/WebKit/Source/platform/text/CompressibleString.cpp
deleted file mode 100644
index 3b7f6c394ca847483967aeea680b931481344c80..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/platform/text/CompressibleString.cpp
+++ /dev/null
@@ -1,129 +0,0 @@
-// 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.
-
-#include "platform/text/CompressibleString.h"
-
-#include "platform/Histogram.h"
-#include "wtf/Assertions.h"
-#include "wtf/WTFThreadData.h"
-#include "wtf/text/WTFString.h"
-
-namespace blink {
-
-class CompressibleStringTable {
-    WTF_MAKE_NONCOPYABLE(CompressibleStringTable);
-public:
-    static CompressibleStringTable* create(WTFThreadData& data)
-    {
-        data.m_compressibleStringTable = new CompressibleStringTable;
-        data.m_compressibleStringTableDestructor = CompressibleStringTable::destroy;
-        return data.m_compressibleStringTable;
-    }
-
-    void add(CompressibleStringImpl* string)
-    {
-        ASSERT(!m_table.contains(string));
-        m_table.add(string);
-    }
-
-    bool contains(CompressibleStringImpl* string) const
-    {
-        return m_table.contains(string);
-    }
-
-    void remove(CompressibleStringImpl* string)
-    {
-        ASSERT(m_table.contains(string));
-        m_table.remove(string);
-    }
-
-    void compressAll()
-    {
-        HashSet<CompressibleStringImpl*>::iterator end = m_table.end();
-        for (HashSet<CompressibleStringImpl*>::iterator iter = m_table.begin(); iter != end; ++iter) {
-            CompressibleStringImpl* string = *iter;
-            if (!string->isCompressed())
-                string->compressString();
-        }
-    }
-
-private:
-    CompressibleStringTable() { }
-
-    static void destroy(CompressibleStringTable* table)
-    {
-        delete table;
-    }
-
-    HashSet<CompressibleStringImpl*> m_table;
-};
-
-static inline CompressibleStringTable& compressibleStringTable()
-{
-    WTFThreadData& data = wtfThreadData();
-    CompressibleStringTable* table = data.compressibleStringTable();
-    if (UNLIKELY(!table))
-        table = CompressibleStringTable::create(data);
-    return *table;
-}
-
-static const unsigned CompressibleStringImplSizeThrehold = 100000;
-
-void CompressibleStringImpl::compressAll()
-{
-    compressibleStringTable().compressAll();
-}
-
-CompressibleStringImpl::CompressibleStringImpl(PassRefPtr<StringImpl> impl)
-    : m_string(impl)
-    , m_isCompressed(false)
-{
-    if (originalContentSizeInBytes() > CompressibleStringImplSizeThrehold)
-        compressibleStringTable().add(this);
-}
-
-CompressibleStringImpl::~CompressibleStringImpl()
-{
-    if (originalContentSizeInBytes() > CompressibleStringImplSizeThrehold)
-        compressibleStringTable().remove(this);
-}
-
-enum CompressibleStringCountType {
-    StringWasCompressedInBackgroundTab,
-    StringWasDecompressed,
-    CompressibleStringCountTypeMax = StringWasDecompressed,
-};
-
-static void recordCompressibleStringCount(CompressibleStringCountType type)
-{
-    DEFINE_THREAD_SAFE_STATIC_LOCAL(EnumerationHistogram, sringTypeHistogram, new EnumerationHistogram("Memory.CompressibleStringCount", CompressibleStringCountTypeMax + 1));
-    sringTypeHistogram.count(type);
-}
-
-// compressString does nothing but collect UMA so far.
-// TODO(hajimehoshi): Implement this.
-void CompressibleStringImpl::compressString()
-{
-    recordCompressibleStringCount(StringWasCompressedInBackgroundTab);
-    ASSERT(!isCompressed());
-    m_isCompressed = true;
-}
-
-// decompressString does nothing but collect UMA so far.
-// TODO(hajimehoshi): Implement this.
-void CompressibleStringImpl::decompressString()
-{
-    // TODO(hajimehoshi): We wanted to tell whether decompressing in a
-    // background tab or a foreground tab, but this was impossible. For example,
-    // one renderer process of a new tab page is used for multiple tabs.
-    // Another example is that reloading a page will re-use the process with a
-    // new Page object and updating a static variable along with reloading will
-    // be complex. See also crbug/581266. We will revisit when the situation
-    // changes.
-    recordCompressibleStringCount(StringWasDecompressed);
-    ASSERT(isCompressed());
-    m_isCompressed = false;
-}
-
-} // namespace blink