[Oilpan] Unify memory usage reporters of Oilpan

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 637100d5f8eb42d30327a9ce160010aaeeb1702a..34e9c173b8ae4e25748d5c6025626a0d91bbad9a 100644
--- a/third_party/WebKit/Source/platform/heap/HeapPage.cpp
+++ b/third_party/WebKit/Source/platform/heap/HeapPage.cpp
@@ -30,6 +30,7 @@
 
 #include "platform/heap/HeapPage.h"
 
+#include "platform/MemoryUsageProvider.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/Task.h"
 #include "platform/TraceEvent.h"
@@ -701,6 +702,8 @@ Address NormalPageHeap::outOfLineAllocate(size_t allocationSize, size_t gcInfoIn
     ASSERT(allocationSize > remainingAllocationSize());
     ASSERT(allocationSize >= allocationGranularity);
 
+    MemoryUsageProvider::instance()->adjustAmountOfAllocatedMemory();

[peria, 2016/02/04 08:33:51]

Currently this is the only entry point to report memory usages.
It means Blink reports almost nothing about deallocations now.

+
     // 1. If this allocation is big enough, allocate a large object.
     if (allocationSize >= largeObjectSizeThreshold) {
         // TODO(sof): support eagerly finalized large objects, if ever needed.