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

components/cronet/ios/Cronet.h

Index: components/cronet/ios/Cronet.h
diff --git a/components/cronet/ios/Cronet.h b/components/cronet/ios/Cronet.h
index 5c867a640fa264573ad5094ea7568f7fff70314f..52f81d9f348b124dadb47e6dff4b12cc59ea5830 100644
--- a/components/cronet/ios/Cronet.h
+++ b/components/cronet/ios/Cronet.h
@@ -12,13 +12,13 @@
 
 // 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
@@ -42,7 +42,7 @@ GRPC_SUPPORT_EXPORT
 // 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.