Update cronet test comments and structure

src/objective-c/tests/CoreCronetEnd2EndTests/CoreCronetEnd2EndTests.m

@@ -32,7 +32,7 @@
  */
 
 #import <XCTest/XCTest.h>
-#include "./h2_ssl_cronet.h"
+#import "src/objective-c/tests/CoreCronetEnd2EndTests/fixture.h"
 
 @interface CoreCronetEnd2EndTests : XCTestCase
 
@@ -42,6 +42,15 @@
 
 - (void)testCoreCronetEnd2End {
   char *argv[] = {"h2_ssl"};
+
+  // This main() function is not the entry point of this test case; it
+  // refers to that in h2_ssl_cronet.m. We can use it because XCode
+  // builder does not use main() as the entry point for a test.
+  // Since h2_ssl_cronet.m is derived from h2_ssl.c in the core end2end
+  // test fixture, we preserves the fixture structure (in particular
+  // the main() function here) so that another fixture can easily
+  // replace the fixture h2_ssl_cronet, in case we need more tests in
+  // the future
   main(1, argv);
 }
 

src/objective-c/tests/CoreCronetEnd2EndTests/fixture.h

@@ -31,9 +31,4 @@
  *
  */
 
-#ifndef GRPC_H2_SSL_H
-#define GRPC_H2_SSL_H
-
-int main(int argc, char **argv);
-
-#endif /* GRPC_H2_SSL_H */
+int main(int argc, char **argv);

src/objective-c/tests/CoreCronetEnd2EndTests/h2_ssl_cronet.m

@@ -32,6 +32,9 @@
  */
 
 /* 
+ * This fixture derives from h2_ssl.c fixture in core end2end test
+ * (test/core/end2end/fixture/h2_ssl.c)
+ *
  * This fixture creates a server full stack using chttp2 and a client
  * full stack using Cronet. End-to-end tests are run against this fixture
  * setting.

src/objective-c/tests/Tests.xcodeproj/project.pbxproj

@@ -110,8 +110,8 @@
 		51A275E86C141416ED63FF76 /* Pods-InteropTestsLocalCleartext.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-InteropTestsLocalCleartext.release.xcconfig"; path = "Pods/Target Support Files/Pods-InteropTestsLocalCleartext/Pods-InteropTestsLocalCleartext.release.xcconfig"; sourceTree = "<group>"; };
 		553BBBED24E4162D1F769D65 /* Pods-InteropTestsLocalSSL.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-InteropTestsLocalSSL.debug.xcconfig"; path = "Pods/Target Support Files/Pods-InteropTestsLocalSSL/Pods-InteropTestsLocalSSL.debug.xcconfig"; sourceTree = "<group>"; };
 		5761E98978DDDF136A58CB7E /* Pods-AllTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-AllTests.release.xcconfig"; path = "Pods/Target Support Files/Pods-AllTests/Pods-AllTests.release.xcconfig"; sourceTree = "<group>"; };
-		5E1BD3B01D3D583900A47325 /* h2_ssl_cronet.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = h2_ssl_cronet.h; sourceTree = "<group>"; };
 		5E1BD3B11D3D583900A47325 /* h2_ssl_cronet.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = h2_ssl_cronet.m; sourceTree = "<group>"; };
+		5E1BD3B31D3D736C00A47325 /* fixture.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = fixture.h; sourceTree = "<group>"; };
 		5E8A5DA41D3840B4000F8BC4 /* CoreCronetEnd2EndTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = CoreCronetEnd2EndTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		5E8A5DA61D3840B4000F8BC4 /* CoreCronetEnd2EndTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CoreCronetEnd2EndTests.m; sourceTree = "<group>"; };
 		6312AE4D1B1BF49B00341DEE /* GRPCClientTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = GRPCClientTests.m; sourceTree = "<group>"; };
@@ -252,7 +252,7 @@
 		5E8A5DA51D3840B4000F8BC4 /* CoreCronetEnd2EndTests */ = {
 			isa = PBXGroup;
 			children = (
-				5E1BD3B01D3D583900A47325 /* h2_ssl_cronet.h */,
+				5E1BD3B31D3D736C00A47325 /* fixture.h */,
 				5E1BD3B11D3D583900A47325 /* h2_ssl_cronet.m */,
 				5E8A5DA61D3840B4000F8BC4 /* CoreCronetEnd2EndTests.m */,
 			);