Refactor Pickle Read methods to use higher performance PickleIterator.

chrome/browser/sessions/compress_data_helper.h

Index: chrome/browser/sessions/compress_data_helper.h
diff --git a/chrome/browser/sessions/compress_data_helper.h b/chrome/browser/sessions/compress_data_helper.h
index d7cbbaae4718979ffd56420cd93e3428b3a9fcd2..0dc078c30faf8d7d24cff95f0789a552d794a065 100644
--- a/chrome/browser/sessions/compress_data_helper.h
+++ b/chrome/browser/sessions/compress_data_helper.h
@@ -11,6 +11,7 @@
 #include <string>
 
 class Pickle;
+class PickleReader;
 
 class CompressDataHelper {
  public:
@@ -25,7 +26,7 @@ class CompressDataHelper {
   // indicates the position of the data. The same iterator is used by
   // Pickle::Read* functions.
   static bool ReadAndDecompressStringFromPickle(const Pickle& pickle,
-                                                void** iter,
+                                                PickleReader* iter,
                                                 std::string* str);
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(CompressDataHelper);