Revert making headers lowercase in FakeUrlResponse

We had made response header names lowercase because they are case
insensitive. It turns out UrlResponseInfoImpl already uses a TreeMap
with a case insensitive order. Map keys will always be case insensitive
anyway, but it could be confusing to users if we change the case of the
headers.

Original Discussion: crrev.com/c/1703325/36/components/cronet/android/fake/java/org/chromium/net/test/FakeUrlRequest.java#203

Bug: 669707
Change-Id: If8af8faf9214fba51e2dceab28e8dcb82976b8ea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1762356
Commit-Queue: Benjamin Kirchman <kirchman@google.com>
Reviewed-by: Paul Jensen <pauljensen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#689123}

components/cronet/android/fake/java/org/chromium/net/test/FakeUrlResponse.java

@@ -12,7 +12,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 
@@ -126,8 +125,7 @@ public class FakeUrlResponse {
          * @return a builder with the corresponding header set
          */
         public Builder addHeader(String name, String value) {
-            mAllHeadersList.add(
-                    new AbstractMap.SimpleEntry<>(name.toLowerCase(Locale.ROOT), value));
+            mAllHeadersList.add(new AbstractMap.SimpleEntry<>(name, value));
             return this;
         }
 

components/cronet/android/fake/javatests/org/chromium/net/test/FakeUrlResponseTest.java

@@ -118,8 +118,7 @@ public class FakeUrlResponseTest {
         String nameNotInOriginalList = "nameNotInOriginalList";
         String valueNotInOriginalList = "valueNotInOriginalList";
         AbstractMap.SimpleEntry<String, String> entryNotInOriginalList =
-                new AbstractMap.SimpleEntry<>(
-                        nameNotInOriginalList.toLowerCase(Locale.ROOT), valueNotInOriginalList);
+                new AbstractMap.SimpleEntry<>(nameNotInOriginalList, valueNotInOriginalList);
 
         FakeUrlResponse testResponseWithHeader =
                 mTestResponse.toBuilder()
@@ -202,4 +201,18 @@ public class FakeUrlResponseTest {
         assertNotEquals(
                 defaultResponse.getAllHeadersList(), defaultResponseWithHeader.getAllHeadersList());
     }
+
+    @Test
+    @SmallTest
+    public void testUrlResponseInfoHeadersMapIsCaseInsensitve() {
+        UrlResponseInfo info = new UrlResponseInfoImpl(new ArrayList<>(), 200, "OK",
+                mTestResponse.getAllHeadersList(), mTestResponse.getWasCached(),
+                mTestResponse.getNegotiatedProtocol(), mTestResponse.getProxyServer(),
+                mTestResponse.getResponseBody().length);
+
+        Map infoMap = info.getAllHeaders();
+
+        assertTrue(infoMap.containsKey(TEST_HEADER_NAME.toLowerCase(Locale.ROOT)));
+        assertTrue(infoMap.containsKey(TEST_HEADER_NAME.toUpperCase(Locale.ROOT)));
+    }
 }