Fix DriveApiRequestsTest.EmptyBatchUploadRequest in official builds.

Official builds don't include strings for CHECKs, so don't check for text.
Right now, the test is failing like so when doing an official build:

..\..\google_apis\drive\drive_api_requests_unittest.cc(2000): error: Death test: request->Commit()
    Result: died but not with expected error.
  Expected: Check failed
Actual msg:

BUG=467929
TBR=hirono@chromium.org

Review URL: https://codereview.chromium.org/1052553004

Cr-Commit-Position: refs/heads/master@{#325246}

google_apis/drive/drive_api_requests_unittest.cc

@@ -1997,7 +1997,7 @@ TEST_F(DriveApiRequestsTest, BatchUploadRequest) {
 TEST_F(DriveApiRequestsTest, EmptyBatchUploadRequest) {
   scoped_ptr<drive::BatchUploadRequest> request(new drive::BatchUploadRequest(
       request_sender_.get(), *url_generator_));
-  EXPECT_DEATH(request->Commit(), "Check failed");
+  EXPECT_DEATH(request->Commit(), "");
 }
 
 }  // namespace google_apis