Add tools for code coverage support in iOS.

ios/showcase/test/showcase_test_case.mm

Index: ios/showcase/test/showcase_test_case.mm
diff --git a/ios/showcase/test/showcase_test_case.mm b/ios/showcase/test/showcase_test_case.mm
index e4877f11f752c2f49acdf50c1365ed9b58d52c2a..a82e4816357c42a93ed89d8749cea4410af22cec 100644
--- a/ios/showcase/test/showcase_test_case.mm
+++ b/ios/showcase/test/showcase_test_case.mm
@@ -7,6 +7,7 @@
 #import <EarlGrey/EarlGrey.h>
 
 #import "base/logging.h"
+#include "testing/coverage_util_ios.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
@@ -14,6 +15,10 @@
 
 @implementation ShowcaseTestCase
 
++ (void)setUp {
+  coverage_util::SetupIfNecessary();

[lpromero, 2017/03/31 11:22:06]

We will also need to add this call to the non-Showcase related targets. Do EG
tests use test_support_ios.mm? If so it would be enough.

+}
+
 // Overrides testInvocations so the set of tests run can be modified, as
 // necessary.
 + (NSArray*)testInvocations {