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..9bedec4c9d19c1e7a49aa2676e07dd764a531302 100644
--- a/net/disk_cache/blockfile/entry_impl.cc
+++ b/net/disk_cache/blockfile/entry_impl.cc
@@ -808,6 +808,14 @@ int32 EntryImpl::GetDataSize(int index) const {
   return entry->Data()->data_size[index];
 }
 
+int EntryImpl::GetEntrySize() const {
+  int result = 0;
+  for (int i = 0; i < kNumStreams; ++i) {
+    result += GetDataSize(i);
+  }
+  return result;
+}
+
 int EntryImpl::ReadData(int index, int offset, IOBuffer* buf, int buf_len,
                         const CompletionCallback& callback) {
   if (callback.is_null())