Pass raw response with Context-Encoding sdch if support is not configured.

components/cronet/ios/test/cronet_http_test.mm

Index: components/cronet/ios/test/cronet_http_test.mm
diff --git a/components/cronet/ios/test/cronet_http_test.mm b/components/cronet/ios/test/cronet_http_test.mm
index 36923e623a6d47a1e42db8a116aa53b87190d019..860c79b1e4e53748537459d8b8002c34d0fd5523 100644
--- a/components/cronet/ios/test/cronet_http_test.mm
+++ b/components/cronet/ios/test/cronet_http_test.mm
@@ -196,6 +196,30 @@ TEST_F(HttpTest, SdchDisabledByDefault) {
   EXPECT_FALSE([[delegate_ responseBody] containsString:@"sdch"]);
 }
 
+TEST_F(HttpTest, AcceptEncodingSdch) {

[xunjieli, 2016/11/29 23:30:42]

I think this deserves a comment and maybe also mention the fact that in the
future we might remove the ability of adding "Accept-Encoding".

[mef, 2016/11/30 15:51:06]

Done.

+  NSURL* url =
+      net::NSURLWithGURL(GURL(TestServer::GetEchoHeaderURL("Accept-Encoding")));
+  NSMutableURLRequest* mutableRequest =
+      [[NSURLRequest requestWithURL:url] mutableCopy];
+  [mutableRequest addValue:@"gzip,sdch" forHTTPHeaderField:@"Accept-Encoding"];
+  NSURLSessionDataTask* task = [session_ dataTaskWithRequest:mutableRequest];
+  StartDataTaskAndWaitForCompletion(task);
+  EXPECT_EQ(nil, [delegate_ error]);
+  EXPECT_TRUE([[delegate_ responseBody] containsString:@"gzip,sdch"]);
+}
+
+TEST_F(HttpTest, AcceptEncodingFooBar) {
+  NSURL* url =
+      net::NSURLWithGURL(GURL(TestServer::GetEchoHeaderURL("Accept-Encoding")));
+  NSMutableURLRequest* mutableRequest =
+      [[NSURLRequest requestWithURL:url] mutableCopy];
+  [mutableRequest addValue:@"foo,bar" forHTTPHeaderField:@"Accept-Encoding"];
+  NSURLSessionDataTask* task = [session_ dataTaskWithRequest:mutableRequest];
+  StartDataTaskAndWaitForCompletion(task);
+  EXPECT_EQ(nil, [delegate_ error]);
+  EXPECT_TRUE([[delegate_ responseBody] containsString:@"foo,bar"]);
+}
+
 TEST_F(HttpTest, NSURLSessionAcceptLanguage) {
   NSURL* url =
       net::NSURLWithGURL(GURL(TestServer::GetEchoHeaderURL("Accept-Language")));