[prof] Add slide offset in dumpcpp script

tools/dumpcpp-driver.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Dump C++ symbols of shared library if possible
+
+function processArguments(args) {
+  var processor = new ArgumentsProcessor(args);
+  if (processor.parse()) {
+    return processor.result();
+  } else {
+    processor.printUsageAndExit();
+  }
+}
+
+function initSourceMapSupport() {
+  // Pull dev tools source maps into our name space.
+  SourceMap = WebInspector.SourceMap;
+
+  // Overwrite the load function to load scripts synchronously.
+  SourceMap.load = function(sourceMapURL) {
+    var content = readFile(sourceMapURL);
+    var sourceMapObject = (JSON.parse(content));
+    return new SourceMap(sourceMapURL, sourceMapObject);
+  };
+}
+
+var entriesProviders = {
+  'unix': UnixCppEntriesProvider,
+  'windows': WindowsCppEntriesProvider,
+  'mac': MacCppEntriesProvider
+};
+
+var params = processArguments(arguments);
+var sourceMap = null;
+if (params.sourceMap) {
+  initSourceMapSupport();
+  sourceMap = SourceMap.load(params.sourceMap);
+}
+
+var cppProcessor = new CppProcessor(
+  new (entriesProviders[params.platform])(params.nm, params.targetRootFS),
+  params.timedRange, params.pairwiseTimedRange);
+cppProcessor.processLogFile(params.logFileName);
+cppProcessor.dumpCppSymbols();