Remove CompressibleStringImpl::s_isPageBackground

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

 // 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 "public/platform/Platform.h"
 #include "wtf/Assertions.h"
 #include "wtf/WTFThreadData.h"
 #include "wtf/text/WTFString.h"
@@ skipping 52 matching lines @@
 {
     WTFThreadData& data = wtfThreadData();
     CompressibleStringTable* table = data.compressibleStringTable();
     if (UNLIKELY(!table))
         table = CompressibleStringTable::create(data);
     return *table;
 }
 
 static const unsigned CompressibleStringImplSizeThrehold = 100000;
 
-bool CompressibleStringImpl::s_isPageBackground = false;
-
 void CompressibleStringImpl::compressAll()
 {
     compressibleStringTable().compressAll();
 }
 
-void CompressibleStringImpl::setPageBackground(bool isPageBackground)
-{
-    s_isPageBackground = isPageBackground;
-}
-
 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,
-    StringWasDecompressedInBackgroundTab,
-    StringWasDecompressedInForegroundTab,
-    CompressibleStringCountTypeMax = StringWasDecompressedInForegroundTab,
+    StringWasDecompressed,
+    CompressibleStringCountTypeMax = StringWasDecompressed,
 };
 
 static void recordCompressibleStringCount(CompressibleStringCountType type)
 {
     Platform::current()->histogramEnumeration("Memory.CompressibleStringCount", type, CompressibleStringCountTypeMax + 1);
 }
 
 // compressString does nothing but collect UMA so far.
 // TODO(hajimehoshi): Implement this.
 void CompressibleStringImpl::compressString()
 {
-    ASSERT(s_isPageBackground);
     recordCompressibleStringCount(StringWasCompressedInBackgroundTab);
     ASSERT(!isCompressed());
     m_isCompressed = true;
 }
 
 // decompressString does nothing but collect UMA so far.
 // TODO(hajimehoshi): Implement this.
 void CompressibleStringImpl::decompressString()
 {
-    if (s_isPageBackground)
-        recordCompressibleStringCount(StringWasDecompressedInBackgroundTab);
-    else
-        recordCompressibleStringCount(StringWasDecompressedInForegroundTab);
-
+    // 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