[inspector] fixed all shorten-64-to-32 warnings

src/inspector/StringUtil.h

 // 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.
 
 #ifndef V8_INSPECTOR_STRINGUTIL_H_
 #define V8_INSPECTOR_STRINGUTIL_H_
 
 #include "src/inspector/Allocator.h"
 #include "src/inspector/String16.h"
 
 #include "include/v8-inspector.h"
 
 namespace v8_inspector {
 
 namespace protocol {
 
 class Value;
 
 using String = v8_inspector::String16;
 using StringBuilder = v8_inspector::String16Builder;
 
 class StringUtil {
  public:
-  static String substring(const String& s, unsigned pos, unsigned len) {
+  static String substring(const String& s, size_t pos, size_t len) {
     return s.substring(pos, len);
   }
   static String fromInteger(int number) { return String::fromInteger(number); }
+  static String fromInteger(size_t number) {
+    return String::fromInteger(number);
+  }
   static String fromDouble(double number) { return String::fromDouble(number); }
   static const size_t kNotFound = String::kNotFound;
-  static void builderReserve(StringBuilder& builder, unsigned capacity) {
+  static void builderReserve(StringBuilder& builder, size_t capacity) {
     builder.reserveCapacity(capacity);
   }
 };
 
 std::unique_ptr<protocol::Value> parseJSON(const StringView& json);
 std::unique_ptr<protocol::Value> parseJSON(const String16& json);
 
 }  // namespace protocol
 
 std::unique_ptr<protocol::Value> toProtocolValue(v8::Local<v8::Context>,
@@ skipping 21 matching lines @@
 
  private:
   explicit StringBufferImpl(String16&);
   String16 m_owner;
   StringView m_string;
 };
 
 }  //  namespace v8_inspector
 
 #endif  // V8_INSPECTOR_STRINGUTIL_H_