Fix Objective-C test pods for Cronet tests

gRPC-Core.podspec

@@ -770,12 +770,16 @@ Pod::Spec.new do |s|
     ss.source_files = 'include/grpc/grpc_cronet.h'
   end
 
+  s.subspec 'Cronet-Implement' do |ss|
+    ss.header_mappings_dir = '.'
+    ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
+                      'src/core/ext/transport/cronet/transport/cronet_transport.c'
+  end
+
   s.subspec 'Cronet-Tests' do |ss|
     ss.header_mappings_dir = '.'
 
-    ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
-                      'src/core/ext/transport/cronet/transport/cronet_transport.c',
-                      'test/core/end2end/cq_verifier.{c,h}',
+    ss.source_files = 'test/core/end2end/cq_verifier.{c,h}',
                       'test/core/end2end/end2end_tests.{c,h}',
                       'test/core/end2end/tests/*.{c,h}',
                       'test/core/end2end/data/*.{c,h}',

src/objective-c/GRPCClient/private/GRPCChannel.h

@@ -59,8 +59,8 @@ struct grpc_channel_credentials;
  * Creates a secure channel to the specified @c host using Cronet as a transport mechanism.
  */
 #ifdef GRPC_COMPILE_WITH_CRONET
-+ (nullable GRPCChannel *)secureCronetChannelWithHost:(NSString *)host
-                                          channelArgs:(NSDictionary *)channelArgs;
++ (nullable GRPCChannel *)secureCronetChannelWithHost:(nonnull NSString *)host
+                                          channelArgs:(nonnull NSDictionary *)channelArgs;
 #endif
 /**
  * Creates a secure channel to the specified @c host using the specified @c credentials and

src/objective-c/tests/Podfile

@@ -14,6 +14,7 @@ GRPC_LOCAL_SRC = '../../..'
   InteropTestsRemote
   InteropTestsLocalSSL
   InteropTestsLocalCleartext
+  InteropTestsRemoteWithCronet
 ).each do |target_name|
   target target_name do
     pod 'Protobuf', :path => "#{GRPC_LOCAL_SRC}/third_party/protobuf", :inhibit_warnings => true
@@ -28,6 +29,11 @@ GRPC_LOCAL_SRC = '../../..'
     pod 'gRPC-RxLibrary', :path => GRPC_LOCAL_SRC
     pod 'gRPC-ProtoRPC',  :path => GRPC_LOCAL_SRC
     pod 'RemoteTest', :path => "RemoteTestClient"
+
+    if target_name == 'InteropTestsRemoteWithCronet'
+      pod 'CronetFramework', :podspec => "#{GRPC_LOCAL_SRC}/src/objective-c"
+      pod 'gRPC-Core/Cronet-Implement', :path => GRPC_LOCAL_SRC
+    end
   end
 end
 
@@ -36,25 +42,10 @@ target 'CoreCronetEnd2EndTests' do
   pod 'CronetFramework', :podspec => "#{GRPC_LOCAL_SRC}/src/objective-c"
   pod 'gRPC-Core', :path => GRPC_LOCAL_SRC
   pod 'gRPC-Core/Cronet-Interface', :path => GRPC_LOCAL_SRC
+  pod 'gRPC-Core/Cronet-Implement', :path => GRPC_LOCAL_SRC
   pod 'gRPC-Core/Cronet-Tests', :path => GRPC_LOCAL_SRC
 end
 
-target 'InteropTestsRemoteWithCronet' do
-  pod 'Protobuf', :path => "#{GRPC_LOCAL_SRC}/third_party/protobuf", :inhibit_warnings => true
-
-  pod '!ProtoCompiler',            :path => "#{GRPC_LOCAL_SRC}/src/objective-c"
-  pod '!ProtoCompiler-gRPCPlugin', :path => "#{GRPC_LOCAL_SRC}/src/objective-c"
-
-  pod 'BoringSSL',       :podspec => "#{GRPC_LOCAL_SRC}/src/objective-c", :inhibit_warnings => true
-  pod 'CronetFramework', :podspec => "#{GRPC_LOCAL_SRC}/src/objective-c"
-  
-  pod 'gRPC',           :path => GRPC_LOCAL_SRC
-  pod 'gRPC-Core',      :path => GRPC_LOCAL_SRC
-  pod 'gRPC-RxLibrary', :path => GRPC_LOCAL_SRC
-  pod 'gRPC-ProtoRPC',  :path => GRPC_LOCAL_SRC
-  pod 'RemoteTest', :path => "RemoteTestClient"
-end
-
 # gRPC-Core.podspec needs to be modified to be successfully used for local development. A Podfile's
 # pre_install hook lets us do that. The block passed to it runs after the podspecs are downloaded
 # and before they are installed in the user project.
@@ -91,7 +82,7 @@ post_install do |installer|
     target.build_configurations.each do |config|
       config.build_settings['GCC_TREAT_WARNINGS_AS_ERRORS'] = 'YES'
     end
-    if target.name == 'gRPC-Core' or target.name == 'gRPC-Core.default-Cronet-Interface-Cronet-Tests'
+    if target.name == 'gRPC-Core' or target.name == 'gRPC-Core.default-Cronet-Implement-Cronet-Interface-Cronet-Tests' or target.name == 'gRPC-Core.default-Cronet-Implement'
       target.build_configurations.each do |config|
         # TODO(zyc): Remove this setting after the issue is resolved
         # GPR_UNREACHABLE_CODE causes "Control may reach end of non-void
@@ -99,5 +90,10 @@ post_install do |installer|
         config.build_settings['GCC_WARN_ABOUT_RETURN_TYPE'] = 'NO'
       end
     end
+    if target.name == 'gRPC'
+      target.build_configurations.each do |config|
+        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] = '$(inherited) COCOAPODS=1 GRPC_COMPILE_WITH_CRONET=1'
+      end
+    end
   end
 end

templates/gRPC-Core.podspec.template

@@ -162,12 +162,16 @@
       ss.source_files = 'include/grpc/grpc_cronet.h'
     end
 
+    s.subspec 'Cronet-Implement' do |ss|
+      ss.header_mappings_dir = '.'
+      ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
+                        'src/core/ext/transport/cronet/transport/cronet_transport.c'
+    end
+
     s.subspec 'Cronet-Tests' do |ss|
       ss.header_mappings_dir = '.'
 
-      ss.source_files = 'src/core/ext/transport/cronet/client/secure/cronet_channel_create.c',
-                        'src/core/ext/transport/cronet/transport/cronet_transport.c',
-                        'test/core/end2end/cq_verifier.{c,h}',
+      ss.source_files = 'test/core/end2end/cq_verifier.{c,h}',
                         'test/core/end2end/end2end_tests.{c,h}',
                         'test/core/end2end/tests/*.{c,h}',
                         'test/core/end2end/data/*.{c,h}',