Enable per thread heap for database thread

third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp

Index: third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
diff --git a/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp b/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
index d49a6126d75856b6990f8cceab7f08f828acedd4..5c505111f40067732fb13148d9b8a62d901fa7a1 100644
--- a/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
+++ b/third_party/WebKit/Source/modules/webdatabase/DatabaseThread.cpp
@@ -45,17 +45,17 @@ DatabaseThread::DatabaseThread()
     , m_cleanupSync(nullptr)
     , m_terminationRequested(false)
 {
+    ASSERT(isMainThread());
 }
 
 DatabaseThread::~DatabaseThread()
 {
-    ASSERT(m_openDatabaseSet.isEmpty());
+    ASSERT(!m_openDatabaseSet);
     ASSERT(!m_thread);
 }
 
 DEFINE_TRACE(DatabaseThread)
 {
-    visitor->trace(m_openDatabaseSet);
     visitor->trace(m_transactionCoordinator);
 }
 
@@ -64,7 +64,7 @@ void DatabaseThread::start()
     ASSERT(isMainThread());
     if (m_thread)
         return;
-    m_thread = WebThreadSupportingGC::create("WebCore: Database");
+    m_thread = WebThreadSupportingGC::create("WebCore: Database", true);
     m_thread->postTask(BLINK_FROM_HERE, threadSafeBind(&DatabaseThread::setupDatabaseThread, this));
 }
 
@@ -94,6 +94,8 @@ void DatabaseThread::terminate()
 
 void DatabaseThread::cleanupDatabaseThread()
 {
+    ASSERT(isDatabaseThread());
+
     WTF_LOG(StorageAPI, "Cleaning up DatabaseThread %p", this);
 
     // Clean up the list of all pending transactions on this database thread
@@ -101,15 +103,15 @@ void DatabaseThread::cleanupDatabaseThread()
 
     // Close the databases that we ran transactions on. This ensures that if any transactions are still open, they are rolled back and we don't leave the database in an
     // inconsistent or locked state.
-    if (m_openDatabaseSet.size() > 0) {
+    if (m_openDatabaseSet) {
         // As the call to close will modify the original set, we must take a copy to iterate over.
-        HeapHashSet<Member<Database>> openSetCopy;
-        openSetCopy.swap(m_openDatabaseSet);
-        HeapHashSet<Member<Database>>::iterator end = openSetCopy.end();
-        for (HeapHashSet<Member<Database>>::iterator it = openSetCopy.begin(); it != end; ++it)
+        HashSet<CrossThreadPersistent<Database>> openSetCopy;
+        openSetCopy.swap(*m_openDatabaseSet);
+        HashSet<CrossThreadPersistent<Database>>::iterator end = openSetCopy.end();
+        for (HashSet<CrossThreadPersistent<Database>>::iterator it = openSetCopy.begin(); it != end; ++it)
             (*it)->close();
+        m_openDatabaseSet = nullptr;
     }
-    m_openDatabaseSet.clear();
 
     m_thread->postTask(BLINK_FROM_HERE, WTF::bind(&DatabaseThread::cleanupDatabaseThreadCompleted, this));
 }
@@ -125,10 +127,12 @@ void DatabaseThread::recordDatabaseOpen(Database* database)
 {
     ASSERT(isDatabaseThread());
     ASSERT(database);
-    ASSERT(!m_openDatabaseSet.contains(database));
+    if (!m_openDatabaseSet)
+        m_openDatabaseSet = adoptPtr(new HashSet<CrossThreadPersistent<Database>>());
+    ASSERT(!m_openDatabaseSet->contains(database));
     MutexLocker lock(m_terminationRequestedMutex);
     if (!m_terminationRequested)
-        m_openDatabaseSet.add(database);
+        m_openDatabaseSet->add(database);
 }
 
 void DatabaseThread::recordDatabaseClosed(Database* database)
@@ -138,10 +142,14 @@ void DatabaseThread::recordDatabaseClosed(Database* database)
 #if ENABLE(ASSERT)
     {
         MutexLocker lock(m_terminationRequestedMutex);
-        ASSERT(m_terminationRequested || m_openDatabaseSet.contains(database));
+        ASSERT(m_terminationRequested || m_openDatabaseSet->contains(database));
     }
 #endif
-    m_openDatabaseSet.remove(database);
+    if (!m_openDatabaseSet) {
+        m_openDatabaseSet->remove(database);
+        if (m_openDatabaseSet->isEmpty())
+            m_openDatabaseSet = nullptr;
+    }
 }
 
 bool DatabaseThread::isDatabaseOpen(Database* database)
@@ -149,7 +157,7 @@ bool DatabaseThread::isDatabaseOpen(Database* database)
     ASSERT(isDatabaseThread());
     ASSERT(database);
     MutexLocker lock(m_terminationRequestedMutex);
-    return !m_terminationRequested && m_openDatabaseSet.contains(database);
+    return !m_terminationRequested && m_openDatabaseSet->contains(database);
 }
 
 bool DatabaseThread::isDatabaseThread() const