Drop dependency on Isolate* from platform.h

src/log.h

 // Copyright 2012 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_LOG_H_
 #define V8_LOG_H_
 
+#include <string>
+
 #include "src/allocation.h"
 #include "src/objects.h"
 #include "src/platform.h"
 #include "src/platform/elapsed-timer.h"
 
 namespace v8 {
 namespace internal {
 
 // Logger is used for collecting logging information from V8 during
 // execution. The result is dumped to a file.
@@ skipping 255 matching lines @@
   void HeapSampleItemEvent(const char* type, int number, int bytes);
   void HeapSampleJSConstructorEvent(const char* constructor,
                                     int number, int bytes);
   void HeapSampleJSRetainersEvent(const char* constructor,
                                          const char* event);
   void HeapSampleJSProducerEvent(const char* constructor,
                                  Address* stack);
   void HeapSampleStats(const char* space, const char* kind,
                        intptr_t capacity, intptr_t used);
 
-  void SharedLibraryEvent(const char* library_path,
-                          uintptr_t start,
-                          uintptr_t end);
-  void SharedLibraryEvent(const wchar_t* library_path,
+  void SharedLibraryEvent(const std::string& library_path,
                           uintptr_t start,
                           uintptr_t end);
 
   // ==== Events logged by --log-timer-events. ====
   enum StartEnd { START, END };
 
   void CodeDeoptEvent(Code* code);
 
   void TimerEvent(StartEnd se, const char* name);
 
@@ skipping 223 matching lines @@
                                  int length) = 0;
 
   NameBuffer* name_buffer_;
 };
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_LOG_H_