Add unit tests target to GN build.

chrome/browser/chrome_content_browser_client_unittest.cc

Index: chrome/browser/chrome_content_browser_client_unittest.cc
diff --git a/chrome/browser/chrome_content_browser_client_unittest.cc b/chrome/browser/chrome_content_browser_client_unittest.cc
index 9ea8f8c972c27be3904709c2d82192bed24813bc..3dd93d9685b0736c4804ac8c33b9b8b493adee27 100644
--- a/chrome/browser/chrome_content_browser_client_unittest.cc
+++ b/chrome/browser/chrome_content_browser_client_unittest.cc
@@ -32,6 +32,8 @@ TEST_F(ChromeContentBrowserClientTest, ShouldAssignSiteForURL) {
   EXPECT_TRUE(client.ShouldAssignSiteForURL(GURL("https://www.google.com")));
 }
 
+#if defined(ENABLE_WEBRTC)
+
 // NOTE: Any updates to the expectations in these tests should also be done in
 // the browser test WebRtcDisableEncryptionFlagBrowserTest.
 class DisableWebRtcEncryptionFlagTest : public testing::Test {
@@ -87,6 +89,8 @@ TEST_F(DisableWebRtcEncryptionFlagTest, StableChannel) {
   EXPECT_FALSE(to_command_line_.HasSwitch(switches::kDisableWebRtcEncryption));
 }
 
+#endif  // ENABLE_WEBRTC
+
 }  // namespace chrome
 
 #if !defined(OS_IOS) && !defined(OS_ANDROID)