V8ScriptValueSerializer: Use PartitionAlloc for the buffer, and avoid copying it into a String.
This causes v8::ValueSerializer to use the buffer partition for its allocations, then
holds the result in a unique_ptr within the SerializedScriptValue. Removal of the String
alternative is expected to follow eventually.
PartitionAlloc has much more consistent cross-platform performance. In particular,
large performance issues with default malloc on Android are blocking this feature from
shipping at present.
BUG=148757
Review-Url: https://codereview.chromium.org/2494823002
Cr-Commit-Position: refs/heads/master@{#432232}
9 files changed
