Revert of Switch wtf/SpinLock to std::atomic

third_party/WebKit/Source/wtf/PartitionAlloc.cpp

Index: third_party/WebKit/Source/wtf/PartitionAlloc.cpp
diff --git a/third_party/WebKit/Source/wtf/PartitionAlloc.cpp b/third_party/WebKit/Source/wtf/PartitionAlloc.cpp
index a71dd0053b92d34dbe75649ed3be8605548749e8..8e6cdd9f4be257ac5b09fe91a7a32e5fe1482061 100644
--- a/third_party/WebKit/Source/wtf/PartitionAlloc.cpp
+++ b/third_party/WebKit/Source/wtf/PartitionAlloc.cpp
@@ -55,7 +55,7 @@
 
 namespace WTF {
 
-SpinLock PartitionRootBase::gInitializedLock;
+int PartitionRootBase::gInitializedLock = 0;
 bool PartitionRootBase::gInitialized = false;
 PartitionPage PartitionRootBase::gSeedPage;
 PartitionBucket PartitionRootBase::gPagedBucket;
@@ -104,15 +104,15 @@
 static void partitionAllocBaseInit(PartitionRootBase* root)
 {
     ASSERT(!root->initialized);
-    {
-        SpinLock::Guard guard(PartitionRootBase::gInitializedLock);
-        if (!PartitionRootBase::gInitialized) {
-            PartitionRootBase::gInitialized = true;
-            // We mark the seed page as free to make sure it is skipped by our
-            // logic to find a new active page.
-            PartitionRootBase::gPagedBucket.activePagesHead = &PartitionRootGeneric::gSeedPage;
-        }
-    }
+
+    spinLockLock(&PartitionRootBase::gInitializedLock);
+    if (!PartitionRootBase::gInitialized) {
+        PartitionRootBase::gInitialized = true;
+        // We mark the seed page as free to make sure it is skipped by our
+        // logic to find a new active page.
+        PartitionRootBase::gPagedBucket.activePagesHead = &PartitionRootGeneric::gSeedPage;
+    }
+    spinLockUnlock(&PartitionRootBase::gInitializedLock);
 
     root->initialized = true;
     root->totalSizeOfCommittedPages = 0;
@@ -166,7 +166,7 @@
 
 void partitionAllocGenericInit(PartitionRootGeneric* root)
 {
-    SpinLock::Guard guard(root->lock);
+    spinLockLock(&root->lock);
 
     partitionAllocBaseInit(root);
 
@@ -243,6 +243,8 @@
     // And there's one last bucket lookup that will be hit for e.g. malloc(-1),
     // which tries to overflow to a non-existant order.
     *bucketPtr = &PartitionRootGeneric::gPagedBucket;
+
+    spinLockUnlock(&root->lock);
 }
 
 static bool partitionAllocShutdownBucket(PartitionBucket* bucket)
@@ -291,7 +293,7 @@
 
 bool partitionAllocGenericShutdown(PartitionRootGeneric* root)
 {
-    SpinLock::Guard guard(root->lock);
+    spinLockLock(&root->lock);
     bool foundLeak = false;
     size_t i;
     for (i = 0; i < kGenericNumBuckets; ++i) {
@@ -299,6 +301,7 @@
         foundLeak |= partitionAllocShutdownBucket(bucket);
     }
     foundLeak |= partitionAllocBaseShutdown(root);
+    spinLockUnlock(&root->lock);
     return !foundLeak;
 }
 
@@ -1238,7 +1241,7 @@
 
 void partitionPurgeMemoryGeneric(PartitionRootGeneric* root, int flags)
 {
-    SpinLock::Guard guard(root->lock);
+    spinLockLock(&root->lock);
     if (flags & PartitionPurgeDecommitEmptyPages)
         partitionDecommitEmptyPages(root);
     if (flags & PartitionPurgeDiscardUnusedSystemPages) {
@@ -1248,6 +1251,7 @@
                 partitionPurgeBucket(bucket);
         }
     }
+    spinLockUnlock(&root->lock);
 }
 
 static void partitionDumpPageStats(PartitionBucketMemoryStats* statsOut, const PartitionPage* page)
@@ -1325,28 +1329,28 @@
     uint32_t directMapLengths[kMaxReportableDirectMaps];
     size_t numDirectMappedAllocations = 0;
 
-    {
-        SpinLock::Guard guard(partition->lock);
-
-        for (size_t i = 0; i < kGenericNumBuckets; ++i) {
-            const PartitionBucket* bucket = &partition->buckets[i];
-            // Don't report the pseudo buckets that the generic allocator sets up in
-            // order to preserve a fast size->bucket map (see
-            // partitionAllocGenericInit for details).
-            if (!bucket->activePagesHead)
-                bucketStats[i].isValid = false;
-            else
-                partitionDumpBucketStats(&bucketStats[i], bucket);
-        }
-
-        for (PartitionDirectMapExtent* extent = partition->directMapList; extent; extent = extent->nextExtent) {
-            ASSERT(!extent->nextExtent || extent->nextExtent->prevExtent == extent);
-            directMapLengths[numDirectMappedAllocations] = extent->bucket->slotSize;
-            ++numDirectMappedAllocations;
-            if (numDirectMappedAllocations == kMaxReportableDirectMaps)
-                break;
-        }
-    }
+    spinLockLock(&partition->lock);
+
+    for (size_t i = 0; i < kGenericNumBuckets; ++i) {
+        const PartitionBucket* bucket = &partition->buckets[i];
+        // Don't report the pseudo buckets that the generic allocator sets up in
+        // order to preserve a fast size->bucket map (see
+        // partitionAllocGenericInit for details).
+        if (!bucket->activePagesHead)
+            bucketStats[i].isValid = false;
+        else
+            partitionDumpBucketStats(&bucketStats[i], bucket);
+    }
+
+    for (PartitionDirectMapExtent* extent = partition->directMapList; extent; extent = extent->nextExtent) {
+        ASSERT(!extent->nextExtent || extent->nextExtent->prevExtent == extent);
+        directMapLengths[numDirectMappedAllocations] = extent->bucket->slotSize;
+        ++numDirectMappedAllocations;
+        if (numDirectMappedAllocations == kMaxReportableDirectMaps)
+            break;
+    }
+
+    spinLockUnlock(&partition->lock);
 
     // partitionsDumpBucketStats is called after collecting stats because it
     // can try to allocate using PartitionAllocGeneric and it can't obtain the