IDB: "Put" support

<rdar://problem/15779643> and https://bugs.webkit.org/show_bug.cgi?id=127401

Reviewed by Alexey Proskuryakov.

Source/WebCore:

Add persistent encode/decode for storage to the database:
* Modules/indexeddb/IDBKey.cpp:
(WebCore::IDBKey::encode):
(WebCore::IDBKey::decode):
* Modules/indexeddb/IDBKey.h:

Add a data class to represent IDBKey suitable for crossing IPC:
* Modules/indexeddb/IDBKeyData.cpp: Added.
(WebCore::IDBKeyData::IDBKeyData):
(WebCore::IDBKeyData::maybeCreateIDBKey):
(WebCore::IDBKeyData::isolatedCopy):
* Modules/indexeddb/IDBKeyData.h: Added.
(WebCore::IDBKeyData::IDBKeyData):

* platform/CrossThreadCopier.cpp:
(WebCore::IDBKeyData>::copy):
* platform/CrossThreadCopier.h:

* WebCore.exp.in:
* WebCore.xcodeproj/project.pbxproj:

Source/WebKit2:

Ship putRecord requests over to the DatabaseProcess, and listen for completion from the DatabaseProcess:
* WebProcess/Databases/IndexedDB/WebIDBServerConnection.cpp:
(WebKit::WebIDBServerConnection::put):
(WebKit::WebIDBServerConnection::didPutRecord):
* WebProcess/Databases/IndexedDB/WebIDBServerConnection.h:
* WebProcess/Databases/IndexedDB/WebIDBServerConnection.messages.in:

Pass off the putRecord request to the Unique IDBDatabase:
* DatabaseProcess/IndexedDB/DatabaseProcessIDBConnection.cpp:
(WebKit::DatabaseProcessIDBConnection::putRecord):
* DatabaseProcess/IndexedDB/DatabaseProcessIDBConnection.h:
* DatabaseProcess/IndexedDB/DatabaseProcessIDBConnection.messages.in:

Pass off the putRecord request to the backing store:
* DatabaseProcess/IndexedDB/UniqueIDBDatabase.cpp:
(WebKit::UniqueIDBDatabase::putRecord):
(WebKit::UniqueIDBDatabase::putRecordInBackingStore):
(WebKit::UniqueIDBDatabase::didPutRecordInBackingStore):
* DatabaseProcess/IndexedDB/UniqueIDBDatabase.h:

Add backing store methods related to putRecord, though only one is critical right now:
* DatabaseProcess/IndexedDB/UniqueIDBDatabaseBackingStore.h:
* DatabaseProcess/IndexedDB/sqlite/UniqueIDBDatabaseBackingStoreSQLite.cpp:
(WebKit::UniqueIDBDatabaseBackingStoreSQLite::createAndPopulateInitialMetadata):
(WebKit::UniqueIDBDatabaseBackingStoreSQLite::generateKey):
(WebKit::UniqueIDBDatabaseBackingStoreSQLite::keyExistsInObjectStore):
(WebKit::UniqueIDBDatabaseBackingStoreSQLite::putRecord):
(WebKit::UniqueIDBDatabaseBackingStoreSQLite::updateKeyGenerator):
* DatabaseProcess/IndexedDB/sqlite/UniqueIDBDatabaseBackingStoreSQLite.h:

Add the IDBKeyData type to IPC:
* Scripts/webkit2/messages.py:
(struct_or_class):

* Shared/WebCoreArgumentCoders.cpp:
(IPC::ArgumentCoder<IDBKeyData>::encode):
(IPC::ArgumentCoder<IDBKeyData>::decode):
* Shared/WebCoreArgumentCoders.h:

* DatabaseProcess/IndexedDB/IDBSerialization.cpp:
(WebKit::serializeIDBKey):
* DatabaseProcess/IndexedDB/IDBSerialization.h:

Implement more cross-thread copying:
* Shared/WebCrossThreadCopier.cpp:
(WebCore::Vector<uint8_t>>::copy):
(WebCore::Vector<Vector<IDBKeyData>>>::copy):
(WebCore::ASCIILiteral>::copy):
* Shared/WebCrossThreadCopier.h:

Implement more numbers of generic AsyncTask templates:
* Shared/AsyncTask.h:
(WebKit::createAsyncTask):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162566 268f45cc-cd09-0410-ab3c-d52691b4dbfc