Remove CFX_BufferSeekableReadStream.

Replace it with CFX_ReadOnlyMemoryStream, which does the same thing.
Take some checks from CFX_BufferSeekableReadStream and add them
CFX_ReadOnlyMemoryStream.

Change-Id: I25554c3aec3ec96967f8df16ca68a64dba121b6f
Reviewed-on: https://pdfium-review.googlesource.com/40070
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 2 insertions, 42 deletions

diff --git a/testing/fuzzers/xfa_codec_fuzzer.h b/testing/fuzzers/xfa_codec_fuzzer.h
index bc40f653af..fe9e72b89d 100644
--- a/testing/fuzzers/xfa_codec_fuzzer.h
+++ b/testing/fuzzers/xfa_codec_fuzzer.h
@@ -9,8 +9,8 @@
 
 #include "core/fxcodec/codec/ccodec_progressivedecoder.h"
 #include "core/fxcodec/fx_codec.h"
+#include "core/fxcrt/cfx_readonlymemorystream.h"
 #include "core/fxge/dib/cfx_dibitmap.h"
-#include "testing/fx_string_testhelpers.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/span.h"
 
@@ -53,7 +53,7 @@ class XFACodecFuzzer {
 
     std::unique_ptr<CCodec_ProgressiveDecoder> decoder =
         mgr->CreateProgressiveDecoder();
-    auto source = pdfium::MakeRetain<CFX_BufferSeekableReadStream>(
+    auto source = pdfium::MakeRetain<CFX_ReadOnlyMemoryStream>(
         pdfium::make_span(data, size));
     FXCODEC_STATUS status = decoder->LoadImageInfo(source, type, nullptr, true);
     if (status != FXCODEC_STATUS_FRAME_READY)
diff --git a/testing/fx_string_testhelpers.cpp b/testing/fx_string_testhelpers.cpp
index e3c443ac4e..96f2c64535 100644
--- a/testing/fx_string_testhelpers.cpp
+++ b/testing/fx_string_testhelpers.cpp
@@ -22,24 +22,3 @@ CFX_InvalidSeekableReadStream::CFX_InvalidSeekableReadStream(
     : data_size_(data_size) {}
 
 CFX_InvalidSeekableReadStream::~CFX_InvalidSeekableReadStream() = default;
-
-CFX_BufferSeekableReadStream::CFX_BufferSeekableReadStream(
-    pdfium::span<const uint8_t> data)
-    : data_(data) {}
-
-CFX_BufferSeekableReadStream::~CFX_BufferSeekableReadStream() = default;
-
-bool CFX_BufferSeekableReadStream::ReadBlock(void* buffer,
-                                             FX_FILESIZE offset,
-                                             size_t size) {
-  if (offset < 0 || static_cast<size_t>(offset) >= data_.size())
-    return false;
-
-  if (static_cast<size_t>(offset) + size > data_.size())
-    size = data_.size() - static_cast<size_t>(offset);
-  if (size == 0)
-    return false;
-
-  memcpy(buffer, &data_[offset], size);
-  return true;
-}
diff --git a/testing/fx_string_testhelpers.h b/testing/fx_string_testhelpers.h
index 4cddefab0a..a828d825ab 100644
--- a/testing/fx_string_testhelpers.h
+++ b/testing/fx_string_testhelpers.h
@@ -32,23 +32,4 @@ class CFX_InvalidSeekableReadStream : public IFX_SeekableReadStream {
   const FX_FILESIZE data_size_;
 };
 
-class CFX_BufferSeekableReadStream : public IFX_SeekableReadStream {
- public:
-  template <typename T, typename... Args>
-  friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
-
-  // IFX_SeekableReadStream:
-  bool ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override;
-
-  FX_FILESIZE GetSize() override {
-    return static_cast<FX_FILESIZE>(data_.size());
-  }
-
- private:
-  explicit CFX_BufferSeekableReadStream(pdfium::span<const uint8_t> data);
-  ~CFX_BufferSeekableReadStream() override;
-
-  pdfium::span<const uint8_t> data_;
-};
-
 #endif  // TESTING_FX_STRING_TESTHELPERS_H_