[Nearby Connections][C++] Fix integer comparison and includes

PiperOrigin-RevId: 385222885

cpp/core/payload.h

@@ -25,6 +25,7 @@
 #include "platform/base/payload_id.h"
 #include "platform/base/prng.h"
 #include "platform/public/file.h"
+#include "platform/public/logging.h"
 #include "absl/types/variant.h"
 
 namespace location {
@@ -94,7 +95,7 @@ class Payload {
     CHECK(type_ == Type::kFile || type_ == Type::kStream);
     InputFile* file = AsFile();
     if (file != nullptr) {
-      CHECK(offset < file->GetTotalSize());
+      CHECK(file->GetTotalSize() > 0 && offset < (size_t)file->GetTotalSize());
     }
     offset_ = offset;
   }

cpp/platform/base/input_stream.cc

@@ -14,6 +14,7 @@
 
 #include "platform/base/input_stream.h"
 
+#include <algorithm>
 #include <cstddef>
 #include <cstdint>
 
@@ -22,8 +23,9 @@
 
 namespace location {
 namespace nearby {
-
+namespace {
 constexpr size_t kSkipBufferSize = 64 * 1024;
+}  // namespace
 
 ExceptionOr<size_t> InputStream::Skip(size_t offset) {
   size_t bytes_left = offset;