Bug 1892976 - Stop throwing error on nsIClipboard::GetData() when the type isn't available on android; r=geckoview-reviewers,m_kato

Other platforms don't throw error; this patch makes android behave consistently
with other platforms.

Differential Revision: https://phabricator.services.mozilla.com/D208470

widget/android/nsClipboard.cpp

@@ -164,7 +164,7 @@ nsClipboard::GetNativeClipboardData(nsITransferable* aTransferable,
     }
   }
 
-  return NS_ERROR_FAILURE;
+  return NS_OK;
 }
 
 nsresult nsClipboard::EmptyNativeClipboardData(int32_t aWhichClipboard) {

widget/tests/file_test_clipboard.js

@@ -149,5 +149,20 @@ clipboardTypes.forEach(function (clipboardType) {
       // Clear all clipboard data.
       cleanupAllClipboard();
     });
+
+    add_task(function test_unsupport_flavor() {
+      try {
+        is(
+          getClipboardData("foo/bar", clipboardType),
+          null,
+          `Test getData for clipboard type ${clipboardType}`
+        );
+      } catch (e) {
+        ok(
+          false,
+          `getData should not throw error for clipboard type ${clipboardType}`
+        );
+      }
+    });
   }
 });