Making CSSValue Pool thread local

third_party/WebKit/Source/core/css/CSSValuePool.cpp

Index: third_party/WebKit/Source/core/css/CSSValuePool.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSValuePool.cpp b/third_party/WebKit/Source/core/css/CSSValuePool.cpp
index 58102f2c9de0d8aae9a10852a487d39f4ab6a7cd..976975491817808808a111829a18feb2ba3473eb 100644
--- a/third_party/WebKit/Source/core/css/CSSValuePool.cpp
+++ b/third_party/WebKit/Source/core/css/CSSValuePool.cpp
@@ -28,14 +28,20 @@
 #include "core/css/CSSValueList.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/style/ComputedStyle.h"
+#include "platform/heap/Handle.h"
 #include "wtf/Threading.h"
 
 namespace blink {
 
 CSSValuePool& cssValuePool()
 {
-    DEFINE_STATIC_LOCAL(CSSValuePool, pool, (new CSSValuePool));
-    return pool;
+    DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<Persistent<CSSValuePool>>, threadSpecificPool, new ThreadSpecific<Persistent<CSSValuePool>>());
+    Persistent<CSSValuePool>& poolHandle = *threadSpecificPool;
+    if (!poolHandle) {
+        poolHandle = new CSSValuePool();
+        poolHandle.clearOnThreadShutdown();
+    }
+    return *poolHandle;
 }
 
 CSSValuePool::CSSValuePool()
@@ -79,14 +85,6 @@ CSSColorValue* CSSValuePool::createColorValue(RGBA32 rgbValue)
     if (rgbValue == Color::black)
         return m_colorBlack;
 
-    if (!isMainThread()) {
-        // TODO (crbug.com/599659): Make CSS color parsing work properly in a
-        // worker thread.
-        // Currently, ColorValueCache is not thread-safe; so we avoid interacting
-        // with it on a non-main thread.
-        return CSSColorValue::create(rgbValue);
-    }
-
     // Just wipe out the cache and start rebuilding if it gets too big.
     const unsigned maximumColorCacheSize = 512;
     if (m_colorValueCache.size() > maximumColorCacheSize)