Add Dart class for _ExternalUint8ClampedArray and API to allocate it.

runtime/lib/byte_array.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
@@ skipping 656 matching lines @@
 DEFINE_NATIVE_ENTRY(ExternalUint8Array_getIndexed, 2) {
   UNALIGNED_GETTER(ExternalUint8Array, Smi, uint8_t);
 }
 
 
 DEFINE_NATIVE_ENTRY(ExternalUint8Array_setIndexed, 3) {
   UNALIGNED_SETTER(ExternalUint8Array, Smi, Value, uint8_t);
 }
 
 
+// ExternalUint8ClampedArray
+
+DEFINE_NATIVE_ENTRY(ExternalUint8ClampedArray_getIndexed, 2) {
+  UNALIGNED_GETTER(ExternalUint8ClampedArray, Smi, uint8_t);
+}
+
+
+DEFINE_NATIVE_ENTRY(ExternalUint8ClampedArray_setIndexed, 3) {
+  UNALIGNED_SETTER(ExternalUint8ClampedArray, Smi, Value, uint8_t);
+}
+
+
 // ExternalInt16Array
 
 DEFINE_NATIVE_ENTRY(ExternalInt16Array_getIndexed, 2) {
   GETTER(ExternalInt16Array, Smi, int16_t);
 }
 
 
 DEFINE_NATIVE_ENTRY(ExternalInt16Array_setIndexed, 3) {
   SETTER(ExternalInt16Array, Smi, Value, int16_t);
 }
@@ skipping 76 matching lines @@
 DEFINE_NATIVE_ENTRY(ExternalFloat64Array_getIndexed, 2) {
   GETTER(ExternalFloat64Array, Double, double);
 }
 
 
 DEFINE_NATIVE_ENTRY(ExternalFloat64Array_setIndexed, 3) {
   SETTER(ExternalFloat64Array, Double, value, double);
 }
 
 }  // namespace dart