Header file clean up.

Remove runtime.h from object.h.
Move TypeStaticIf to its own header file to avoid bringing utils.h into
allocator.h.
Move Array::DataOffset into -inl.h as it now has a utils.h dependency.
Fix include issues arising from this.

Change-Id: I4605b1aa4ff5f8dc15706a0132e15df03c7c8ba0
diff --git a/runtime/base/type_static_if.h b/runtime/base/type_static_if.h
new file mode 100644
index 0000000..a74d79a
--- /dev/null
+++ b/runtime/base/type_static_if.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_BASE_TYPE_STATIC_IF_H_
+#define ART_RUNTIME_BASE_TYPE_STATIC_IF_H_
+
+// A static if which determines whether to return type A or B based on the condition boolean.
+template <bool condition, typename A, typename B>
+struct TypeStaticIf {
+  typedef A type;
+};
+
+// Specialization to handle the false case.
+template <typename A, typename B>
+struct TypeStaticIf<false, A,  B> {
+  typedef B type;
+};
+
+#endif  // ART_RUNTIME_BASE_TYPE_STATIC_IF_H_