save-data header value gets appended on page refreshes

third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp

Index: third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp b/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
index c000b80742cbc857244ddee763d294e65ee5b7b9..22c206f078a09a3c74fea5f3f19a42c22d2ac78b 100644
--- a/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
@@ -564,6 +564,11 @@ TEST_F(FrameFetchContextTest, EnableDataSaver)
     ResourceRequest resourceRequest("http://www.example.com");
     fetchContext->addAdditionalRequestHeaders(resourceRequest, FetchMainResource);
     EXPECT_STREQ("on", resourceRequest.httpHeaderField("Save-Data").utf8().data());
+
+    // Subsequent call to addAdditionalRequestHeaders should not append to the
+    // save-data header.
+    fetchContext->addAdditionalRequestHeaders(resourceRequest, FetchMainResource);
+    EXPECT_STREQ("on", resourceRequest.httpHeaderField("Save-Data").utf8().data());
 }
 
 TEST_F(FrameFetchContextTest, DisabledDataSaver)