Oilpan: always shrink tail-allocated backing storage (reland.)

third_party/WebKit/Source/platform/heap/HeapPage.cpp

Index: third_party/WebKit/Source/platform/heap/HeapPage.cpp
diff --git a/third_party/WebKit/Source/platform/heap/HeapPage.cpp b/third_party/WebKit/Source/platform/heap/HeapPage.cpp
index a94679f4db7bb3e4aeff837b82613f731354300c..ac605cdb41bcb1aa3c9473f5ef937c6877a1f9bf 100644
--- a/third_party/WebKit/Source/platform/heap/HeapPage.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapPage.cpp
@@ -699,7 +699,7 @@ bool NormalPageHeap::expandObject(HeapObjectHeader* header, size_t newSize)
     size_t allocationSize = Heap::allocationSizeFromSize(newSize);
     ASSERT(allocationSize > header->size());
     size_t expandSize = allocationSize - header->size();
-    if (header->payloadEnd() == m_currentAllocationPoint && expandSize <= m_remainingAllocationSize) {
+    if (isObjectAllocatedLast(header) && expandSize <= m_remainingAllocationSize) {

[haraken, 2015/10/09 14:21:41]

isObjectAllocatedAtAllocationPoint ?

[sof, 2015/10/09 14:26:40]

A bit long, but why not; done.

         m_currentAllocationPoint += expandSize;
         m_remainingAllocationSize -= expandSize;
 
@@ -719,7 +719,7 @@ bool NormalPageHeap::shrinkObject(HeapObjectHeader* header, size_t newSize)
     size_t allocationSize = Heap::allocationSizeFromSize(newSize);
     ASSERT(header->size() > allocationSize);
     size_t shrinkSize = header->size() - allocationSize;
-    if (header->payloadEnd() == m_currentAllocationPoint) {
+    if (isObjectAllocatedLast(header)) {
         m_currentAllocationPoint -= shrinkSize;
         m_remainingAllocationSize += shrinkSize;
         SET_MEMORY_INACCESSIBLE(m_currentAllocationPoint, shrinkSize);