Add configuration functions for HTTP cache type to Obj-C and C++

components/cronet/ios/Cronet.mm

 // 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 "components/cronet/ios/Cronet.h"
 
 #include <memory>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 15 matching lines @@
 class CronetHttpProtocolHandlerDelegate;
 
 // Currently there is one and only one instance of CronetEnvironment,
 // which is leaked at the shutdown. We should consider allowing multiple
 // instances if that makes sense in the future.
 base::LazyInstance<std::unique_ptr<cronet::CronetEnvironment>>::Leaky
     gChromeNet = LAZY_INSTANCE_INITIALIZER;
 
 BOOL gHttp2Enabled = YES;
 BOOL gQuicEnabled = NO;
+HttpCacheType gHttpCache = HttpCacheType::DISK;
 ScopedVector<cronet::URLRequestContextConfig::QuicHint> gQuicHints;
 NSString* gUserAgent = nil;
 BOOL gUserAgentPartial = NO;
 NSString* gSslKeyLogFileName = nil;
 RequestFilterBlock gRequestFilterBlock = nil;
 std::unique_ptr<CronetHttpProtocolHandlerDelegate> gHttpProtocolHandlerDelegate;
 NSURLCache* gPreservedSharedURLCache = nil;
 BOOL gEnableTestCertVerifierForTesting = FALSE;
 
 // CertVerifier, which allows any certificates for testing.
@@ skipping 106 matching lines @@
   [self checkNotStarted];
   gUserAgent = userAgent;
   gUserAgentPartial = partial;
 }
 
 + (void)setSslKeyLogFileName:(NSString*)sslKeyLogFileName {
   [self checkNotStarted];
   gSslKeyLogFileName = sslKeyLogFileName;
 }
 
++ (void)setHttpCacheType:(HttpCacheType)httpCache {
+  [self checkNotStarted];
+  gHttpCache = httpCache;

[mef, 2017/01/18 22:39:51]

I think this is a good place to map from ObjC to HttpCacheType.

[lilyhoughton, 2017/01/19 16:17:15]

Done; there may be a more robust way to map the ObjC enum to the C++ one, by
giving the enumerations explicit int values, so that this can be a simple cast
instead of a switch statement?

I don't know which would be clearest/easiest to maintain, though.

+}
+
 + (void)setRequestFilterBlock:(RequestFilterBlock)block {
   if (gHttpProtocolHandlerDelegate.get())
     gHttpProtocolHandlerDelegate.get()->SetRequestFilterBlock(block);
   else
     gRequestFilterBlock = block;
 }
 
 + (void)startInternal {
   cronet::CronetEnvironment::Initialize();
   std::string user_agent = base::SysNSStringToUTF8(gUserAgent);
   gChromeNet.Get().reset(
       new cronet::CronetEnvironment(user_agent, gUserAgentPartial));
   gChromeNet.Get()->set_accept_language(
       base::SysNSStringToUTF8([self getAcceptLanguages]));
 
   gChromeNet.Get()->set_http2_enabled(gHttp2Enabled);
   gChromeNet.Get()->set_quic_enabled(gQuicEnabled);
+  gChromeNet.Get()->set_http_cache(gHttpCache);
   gChromeNet.Get()->set_ssl_key_log_file_name(
       base::SysNSStringToUTF8(gSslKeyLogFileName));
   for (const auto* quicHint : gQuicHints) {
     gChromeNet.Get()->AddQuicHint(quicHint->host, quicHint->port,
                                   quicHint->alternate_port);
   }
 
   [self configureCronetEnvironmentForTesting:gChromeNet.Get().get()];
   gChromeNet.Get()->Start();
   gHttpProtocolHandlerDelegate.reset(new CronetHttpProtocolHandlerDelegate(
@@ skipping 101 matching lines @@
       base::SysNSStringToUTF8(hostResolverRulesForTesting));
 }
 
 // This is a non-public dummy method that prevents the linker from stripping out
 // the otherwise non-referenced methods from 'bidirectional_stream.cc'.
 + (void)preventStrippingCronetBidirectionalStream {
   bidirectional_stream_create(NULL, 0, 0);
 }
 
 @end