Added external memory counting for IDBValue

third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp

Index: third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp b/third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp
index 279a4ebe86b419f919a3acae3110efeb2a65da8d..5d120e37119e0238491a53450a9e3ab4cabaf174 100644
--- a/third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp
+++ b/third_party/WebKit/Source/modules/indexeddb/IDBValue.cpp
@@ -4,6 +4,9 @@
 
 #include "modules/indexeddb/IDBValue.h"
 
+#include <v8.h>
+
+#include "bindings/core/v8/SerializedScriptValue.h"
 #include "platform/blob/BlobData.h"
 #include "public/platform/WebBlobInfo.h"
 #include "public/platform/modules/indexeddb/WebIDBValue.h"
@@ -15,6 +18,11 @@ IDBValue::IDBValue() = default;
 
 IDBValue::IDBValue(const WebIDBValue& value)
     : IDBValue(value.data, value.webBlobInfo, value.primaryKey, value.keyPath) {
+  m_externalAllocatedSize = true;
+  if (m_data) {
+    v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(
+        m_data->size());
+  }
 }
 
 IDBValue::IDBValue(PassRefPtr<SharedBuffer> data,
@@ -49,7 +57,12 @@ IDBValue::IDBValue(const IDBValue* value,
   }
 }
 
-IDBValue::~IDBValue() {}
+IDBValue::~IDBValue() {
+  if (m_data && m_externalAllocatedSize) {

[cmumford, 2017/02/14 00:59:24]

How about instead having this:

int64_t m_externalAllocatedSize = 0;

in the header, so then you can just

v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(-m_externalAllocatedSize)

[dmurph, 2017/02/14 01:10:01]

I like it - I'm still going to check to see if it's not 0, so we don't execute
the v8 logic if we don't have to.

+    v8::Isolate::GetCurrent()->AdjustAmountOfExternalAllocatedMemory(
+        -m_data->size());
+  }
+}
 
 PassRefPtr<IDBValue> IDBValue::create() {
   return adoptRef(new IDBValue());
@@ -73,8 +86,8 @@ Vector<String> IDBValue::getUUIDs() const {
   return uuids;
 }
 
-const SharedBuffer* IDBValue::data() const {
-  return m_data.get();
+RefPtr<SerializedScriptValue> IDBValue::createSerializedValue() const {
+  return SerializedScriptValue::create(m_data->data(), m_data->size());

[jsbell, 2017/02/14 01:11:34]

Note that this does a data copy (because it does byte swap, for horrible
historical reasons). So we'll end up doubling memory between the IDBValue's
SharedBuffer and the SerializedScriptValue's internal String. And when the SSV
is deserialized to V8 we've added yet another copy to the v8 heap. Wheee.

That's not new, but as a follow-on we should look at de-duping.

It should (in theory...) be the case that once we've deserialized an IDBValue we
should never need to deserialize it again. That's going to be hidden behind the
IDBAny -> v8::Value conversion implicit in IDBRequest::result(). Similarly, once
we've deserialized a SerializedScriptValue (in this case, at least) we should be
able to discard the SSV.

 }
 
 bool IDBValue::isNull() const {