No two error messages at same time.

BUG=628161

When set one of TextEdit, which are mEnterPassphrase and
mConfirmPassphrase, to have an error message, set another one
to empty.

Review-Url: https://codereview.chromium.org/2179093002
Cr-Commit-Position: refs/heads/master@{#407669}

chrome/android/java/src/org/chromium/chrome/browser/sync/ui/PassphraseCreationDialogFragment.java

@@ -107,10 +107,12 @@ public class PassphraseCreationDialogFragment extends DialogFragment {
         String confirmPassphrase = mConfirmPassphrase.getText().toString();
 
         if (!passphrase.equals(confirmPassphrase)) {
+            mEnterPassphrase.setError(null);
             mConfirmPassphrase.setError(getString(R.string.sync_passphrases_do_not_match));
             mConfirmPassphrase.requestFocus();
             return;
         } else if (passphrase.isEmpty()) {
+            mConfirmPassphrase.setError(null);
             mEnterPassphrase.setError(getString(R.string.sync_passphrase_cannot_be_blank));
             mEnterPassphrase.requestFocus();
             return;

chrome/android/sync_shell/javatests/src/org/chromium/chrome/browser/sync/SyncCustomizationFragmentTest.java

@@ -548,32 +548,42 @@ public class SyncCustomizationFragmentTest extends SyncTestBase {
         clickButton(okButton);
         assertTrue(pcdf.isResumed());
         assertNotNull(enterPassphrase.getError());
+        assertNull(confirmPassphrase.getError());
 
         // Error if you try to submit with only the first box filled.
         clearError(confirmPassphrase);
         setText(enterPassphrase, "foo");
         clickButton(okButton);
         assertTrue(pcdf.isResumed());
+        assertNull(enterPassphrase.getError());
         assertNotNull(confirmPassphrase.getError());
 
-        // Error if you try to submit with only the second box filled.
+        // Remove first box should only show empty error message
         setText(enterPassphrase, "");
+        clickButton(okButton);
+        assertNotNull(enterPassphrase.getError());
+        assertNull(confirmPassphrase.getError());
+
+        // Error if you try to submit with only the second box filled.
         clearError(confirmPassphrase);
         setText(confirmPassphrase, "foo");
         clickButton(okButton);
         assertTrue(pcdf.isResumed());
+        assertNull(enterPassphrase.getError());
         assertNotNull(confirmPassphrase.getError());
 
         // No error if text doesn't match without button press.
         setText(enterPassphrase, "foo");
         clearError(confirmPassphrase);
         setText(confirmPassphrase, "bar");
+        assertNull(enterPassphrase.getError());
         assertNull(confirmPassphrase.getError());
 
         // Error if you try to submit unmatching text.
         clearError(confirmPassphrase);
         clickButton(okButton);
         assertTrue(pcdf.isResumed());
+        assertNull(enterPassphrase.getError());
         assertNotNull(confirmPassphrase.getError());
 
         // Success if text matches.