Add a size estimation mechanism to StoragePartitionHttpCacheDataRemover.

net/disk_cache/blockfile/entry_impl.cc

Index: net/disk_cache/blockfile/entry_impl.cc
diff --git a/net/disk_cache/blockfile/entry_impl.cc b/net/disk_cache/blockfile/entry_impl.cc
index c26026e2d788a65bc9064f475b0a2289d13c69e9..f2cc9f1270b27d516d4e0e0117273b036b7d61d2 100644
--- a/net/disk_cache/blockfile/entry_impl.cc
+++ b/net/disk_cache/blockfile/entry_impl.cc
@@ -746,6 +746,14 @@ int EntryImpl::NumBlocksForEntry(int key_size) {
   return ((key_size - key1_len) / 256 + 2);
 }
 
+int EntryImpl::GetEntrySize() const {
+  int result = 0;
+  for (int i = 0; i < kNumStreams; ++i) {
+    result += GetDataSize(i);
+  }
+  return result;
+}
+
 // ------------------------------------------------------------------------
 
 void EntryImpl::Doom() {