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 758f79866bae13e8c2ddbc36fcb7efb65a276cb3..a5d224101045468845897ba4cb250fa8fdcd96b7 100644
--- a/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameFetchContextTest.cpp
@@ -557,6 +557,11 @@ 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)