[IndexedDB] Adding txn, value, and key size metrics

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

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/indexeddb/IDBValueWrapping.h"
 
 #include <utility>
 
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/serialization/SerializationTag.h"
@@ skipping 49 matching lines @@
     SerializedScriptValue::SerializeOptions::WasmSerializationPolicy
         wasm_policy,
     ExceptionState& exception_state) {
   SerializedScriptValue::SerializeOptions options;
   options.blob_info = &blob_info_;
   options.for_storage = SerializedScriptValue::kForStorage;
   options.wasm_policy = wasm_policy;
 
   serialized_value_ = SerializedScriptValue::Serialize(isolate, value, options,
                                                        exception_state);
-
+  if (serialized_value_)
+    original_data_length_ = serialized_value_->DataLengthInBytes();
 #if DCHECK_IS_ON()
   if (exception_state.HadException())
     had_exception_ = true;
 #endif  // DCHECK_IS_ON()
 }
 
 void IDBValueWrapper::Clone(ScriptState* script_state, ScriptValue* clone) {
 #if DCHECK_IS_ON()
   DCHECK(!had_exception_) << __FUNCTION__
                           << " called on wrapper with serialization exception";
@@ skipping 166 matching lines @@
     ++current_;
     value |= static_cast<unsigned>(byte & 0x7F) << shift;
     shift += 7;
 
     has_another_byte = byte & 0x80;
   } while (has_another_byte);
   return true;
 }
 
 }  // namespace blink