Re-enable JSWindowIDManagerTest.WindowID

Creates CRWTestJSWindowIdManager to enable force injection,
bypassing hasBeenInjected check in the inject method.

Moves crw_js_window_id_manager_unittest.mm out of public directory.

BUG=465898

Review URL: https://codereview.chromium.org/1129763003

Cr-Commit-Position: refs/heads/master@{#329438}

ios/web/ios_web_unittests.gyp

@@ -41,7 +41,6 @@
         'net/web_http_protocol_handler_delegate_unittest.mm',
         'public/referrer_util_unittest.cc',
         'public/test/http_server_unittest.mm',
-        'public/web_state/js/crw_js_window_id_manager_unittest.mm',
         'string_util_unittest.cc',
         'test/crw_fake_web_controller_observer_unittest.mm',
         'test/run_all_unittests.cc',
@@ -55,6 +54,7 @@
         'web_state/js/crw_js_early_script_manager_unittest.mm',
         'web_state/js/crw_js_injection_manager_unittest.mm',
         'web_state/js/crw_js_invoke_parameter_queue_unittest.mm',
+        'web_state/js/crw_js_window_id_manager_unittest.mm',
         'web_state/js/page_script_util_unittest.mm',
         'web_state/ui/crw_static_file_web_view_unittest.mm',
         'web_state/ui/crw_ui_simple_web_view_controller_unittest.mm',

ios/web/public/web_state/js/crw_js_window_id_manager_unittest.mm → ios/web/web_state/js/crw_js_window_id_manager_unittest.mm

@@ -6,6 +6,7 @@
 
 #include "base/mac/scoped_nsobject.h"
 #import "ios/web/public/test/crw_test_js_injection_receiver.h"
+#import "ios/web/public/test/js_test_util.h"
 #include "ios/web/public/web_client.h"
 #import "testing/gtest_mac.h"
 #include "testing/platform_test.h"
@@ -33,19 +34,26 @@ class JSWindowIDManagerTest : public PlatformTest {
   web::WebClient web_client_;
 };
 
-// TODO(jyquinn): enable this test (crbug.com/465898).
-TEST_F(JSWindowIDManagerTest, DISABLED_WindowID) {
+// Tests that reinjection of window ID JS results in a different window ID.
+// TODO(ios): This test only works for the current implementation using
+// UIWebView. CRWTestJSInjectionReceiver should be re-written to eliminate
+// web view specificity (crbug.com/486840).
+TEST_F(JSWindowIDManagerTest, WindowIDReinjection) {
   EXPECT_TRUE(manager_.get());
   [manager_ inject];
   NSString* windowID = [manager_ windowId];
   EXPECT_EQ(32U, [windowID length]);
+  // Reset the __gCrWeb object to enable reinjection.
+  web::EvaluateJavaScriptAsString(manager_, @"__gCrWeb = undefined;");
   // Inject a second time to check that the ID is different.
   [manager_ inject];
   NSString* windowID2 = [manager_ windowId];
   EXPECT_FALSE([windowID isEqualToString:windowID2]);
 }
 
-TEST_F(JSWindowIDManagerTest, WindowIDDifferent) {
+// Tests that window ID injection by a second manager results in a different
+// window ID.
+TEST_F(JSWindowIDManagerTest, WindowIDDifferentManager) {
   [manager_ inject];
   NSString* windowID = [manager_ windowId];
   base::scoped_nsobject<CRWTestJSInjectionReceiver> receiver2(