Add IDBKeyRange to dart:html, port two indexeddb tests

tests/html/html.status

Index: tests/html/html.status
diff --git a/tests/html/html.status b/tests/html/html.status
index 00d65e2634cca0aed9ccf2c52e15b153adabb52c..548625b1bde42f5e5926345c8d8996ee48960b8d 100644
--- a/tests/html/html.status
+++ b/tests/html/html.status
@@ -10,6 +10,8 @@ measurement_test: Pass, Fail  # Issue 1940
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) ]
 request_animation_frame_test: Skip   # drt hangs; requestAnimationFrame not implemented
+indexeddb_3_test: Fail  # exception not caught - not 'is IDBDatabaseException' ?
+indexeddb_4_test: Fail  # exception not caught - not 'is IDBDatabaseException' ?
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium) && $mode == debug ]
 native_gc_test: Skip  # Issue 2538. Too slow in debug.
@@ -133,9 +135,6 @@ css_test: Pass, Fail # Test is flaky Issue #2823
 [ $compiler == frog && $runtime == none ]
 *: Skip
 
-[ $compiler == dart2js && ($runtime == drt || $runtime == chrome || $runtime == ff) ]
-request_animation_frame_test: Skip # Async test hangs.
-
 [ $compiler == dart2js && $runtime == drt ]
 # Unknown error - should investigate.
 documentfragment_test: Fail
@@ -151,10 +150,13 @@ svgelement_test: Fail
 dom_isolates_test: Fail # error: cannot resolve spawnDomIsolate
 
 [ $compiler == dart2js && ($runtime == drt || $runtime == chrome || $runtime == ff) ]
+request_animation_frame_test: Skip # Async test hangs.
 isolates_test: Skip   # Timeout because leg does not support web workers.
 typed_arrays_1_test: Fail # dart2js doesn't support is checks with generic types.
 cross_frame_test: Fail # Issue 2774, iframe.contentDocument is accessible in dart:html
 inner_frame_test: Fail # Issue 2774
+indexeddb_3_test: Fail  # TypeError: Object #<IDBCursorWithValue> has no method 'continueFunction'
+indexeddb_4_test: Fail  # TypeError: Object #<IDBCursorWithValue> has no method 'continueFunction'
 
 # DOM errors.
 indexeddb_2_test: Fail # Uncaught error