Add CHECKs to identify what condition is causing the crashes

crash/5186130e462b3265 suggests that the crashes reported in the linked
bugs are happening when result_status != RESULT_STATUS_SUCCESS.
This can be due to time out or internal error.

Adding CHECKs for both of those conditions explicitly to understand
what's causing that.

Bug: 893110,889972
Change-Id: I51598b9642a09b31ad700bc83829636d2787fccd
Reviewed-on: https://chromium-review.googlesource.com/c/1343521Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609728}

components/safe_browsing/android/safe_browsing_api_handler_bridge.cc

@@ -124,13 +124,16 @@ void JNI_SafeBrowsingApiBridge_OnUrlCheckDone(
           callback_id));
 
   if (result_status != RESULT_STATUS_SUCCESS) {
-    CHECK(callback);              // Remove after fixing crbug.com/889972
-    CHECK(!callback->is_null());  // Remove after fixing crbug.com/889972
-
     if (result_status == RESULT_STATUS_TIMEOUT) {
+      CHECK(callback);              // Remove after fixing crbug.com/889972
+      CHECK(!callback->is_null());  // Remove after fixing crbug.com/889972
+
       ReportUmaResult(UMA_STATUS_TIMEOUT);
       VLOG(1) << "Safe browsing API call timed-out";
     } else {
+      CHECK(callback);              // Remove after fixing crbug.com/889972
+      CHECK(!callback->is_null());  // Remove after fixing crbug.com/889972
+
       DCHECK_EQ(result_status, RESULT_STATUS_INTERNAL_ERROR);
       ReportUmaResult(UMA_STATUS_INTERNAL_ERROR);
     }