Reland "Avoid duplicate data buffering in CPDF_SyntaxParser::ReadStream()."

This is a reland of 77f15f7883638a4ced131d74c053af10a5970ce9

Original change's description:
> Avoid duplicate data buffering in CPDF_SyntaxParser::ReadStream().
> 
> Allow sub-streams created from an IFX_SeekableReadStream to provide
> stream data without copying memory.
> The data will only reside in the top-level stream.
> 
> For example:
> For file
> http://www.major-landrover.ru/upload/attachments/f/9/f96aab07dab04ae89c8a509ec1ef2b31.pdf
> (18 Mb)
> 
> The memory usage is reduced by ~13 Mb.
> 
> Change-Id: I2595c014d0fbe1fdd181cc04965cfd7d901c2d88
> Reviewed-on: https://pdfium-review.googlesource.com/35930
> Commit-Queue: Art Snake <art-snake@yandex-team.ru>
> Reviewed-by: dsinclair <dsinclair@chromium.org>

Change-Id: I4c4d5dcf42ff44784468ac7a7c302df509fc804d
Reviewed-on: https://pdfium-review.googlesource.com/37313
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Art Snake <art-snake@yandex-team.ru>

1 files changed, 3 insertions, 1 deletions

diff --git a/testing/embedder_test.cpp b/testing/embedder_test.cpp
index e4ac4ad2c7..e874640218 100644
--- a/testing/embedder_test.cpp
+++ b/testing/embedder_test.cpp
@@ -351,7 +351,9 @@ FPDF_DOCUMENT EmbedderTest::OpenSavedDocument(const char* password) {
   memset(&saved_file_access_, 0, sizeof(saved_file_access_));
   saved_file_access_.m_FileLen = data_string_.size();
   saved_file_access_.m_GetBlock = GetBlockFromString;
-  saved_file_access_.m_Param = &data_string_;
+  // Copy data to prevent clearing it before saved document close.
+  saved_document_file_data_ = data_string_;
+  saved_file_access_.m_Param = &saved_document_file_data_;
 
   saved_fake_file_access_ =
       pdfium::MakeUnique<FakeFileAccess>(&saved_file_access_);