[Cronet] make HttpCacheType enum more comfortative to Obj-C style.

components/cronet/ios/Cronet.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <Foundation/Foundation.h>
 
 #include "bidirectional_stream_c.h"
 
 // TODO(mef): Remove this header after transition to bidirectional_stream_c.h
 // See crbug.com/650462 for details.
 #include "cronet_c_for_grpc.h"
 
 // Type of HTTP cache; public interface to private implementation defined in
 // URLRequestContextConfig class.
-enum HttpCacheType {
+typedef NS_ENUM(NSInteger, CRNHttpCacheType) {

[robgaunt, 2017/02/01 19:46:44]

In objective-C, acronyms and initialisms are conventionally left upper-case. So:
CRNHTTPCacheType

(For example, in iOS system frameworks we have NSURL, NSHTTPURLResponse, etc.)

However, it's OK with me if you want to keep "Http" for consistency with
existing usage in this file.

   // Disabled HTTP cache.  Some data may still be temporarily stored in memory.
-  DISABLED,
+  CRNHttpCacheTypeDisabled,
   // Enable on-disk HTTP cache, including HTTP data.
-  DISK,
+  CRNHttpCacheTypeDisk,
   // Enable in-memory cache, including HTTP data.
-  MEMORY,
+  CRNHttpCacheTypeMemory,
 };
 
 // A block, that takes a request, and returns YES if the request should
 // be handled.
 typedef BOOL (^RequestFilterBlock)(NSURLRequest* request);
 
 // Interface for installing Cronet.
 // TODO(gcasto): Should this macro be separate from the one defined in
 // bidirectional_stream_c.h?
 GRPC_SUPPORT_EXPORT
 @interface Cronet : NSObject
 
 // Sets whether HTTP/2 should be supported by CronetEngine. This method only has
 // any effect before |start| is called.
 + (void)setHttp2Enabled:(BOOL)http2Enabled;
 
 // Sets whether QUIC should be supported by CronetEngine. This method only has
 // any effect before |start| is called.
 + (void)setQuicEnabled:(BOOL)quicEnabled;
 
 // Set HTTP Cache type to be used by CronetEngine.  This method only has any
 // effect before |start| is called.  See HttpCacheType enum for available
 // options.
-+ (void)setHttpCacheType:(HttpCacheType)httpCacheType;
++ (void)setHttpCacheType:(CRNHttpCacheType)httpCacheType;
 
 // Adds hint that host supports QUIC on altPort. This method only has any effect
 // before |start| is called.
 + (void)addQuicHint:(NSString*)host port:(int)port altPort:(int)altPort;
 
 // Sets the User-Agent request header string to be sent with all requests.
 // If |partial| is set to YES, then actual user agent value is based on device
 // model, OS version, and |userAgent| argument. For example "Foo/3.0.0.0" is
 // sent as "Mozilla/5.0 (iPhone; CPU iPhone OS 9_3 like Mac OS X)
 // AppleWebKit/601.1 (KHTML, like Gecko) Foo/3.0.0.0 Mobile/15G31
@@ skipping 72 matching lines @@
 
 // Sets Host Resolver Rules for testing.
 // This method must be called after |start| has been called.
 + (void)setHostResolverRulesForTesting:(NSString*)hostResolverRulesForTesting;
 
 // Enables TestCertVerifier which accepts all certificates for testing.
 // This method only has any effect before |start| is called.
 + (void)enableTestCertVerifierForTesting;
 
 @end