Add DEPS include rules so we don't accidentally use base

ppapi/api/pp_macros.idl

Index: ppapi/api/pp_macros.idl
diff --git a/ppapi/api/pp_macros.idl b/ppapi/api/pp_macros.idl
index f189d4a9361939972cd8bcc43b3cb59ca0480ab2..0801fc639893735bf30c74e6f72fdb06298f0a9c 100644
--- a/ppapi/api/pp_macros.idl
+++ b/ppapi/api/pp_macros.idl
@@ -14,6 +14,38 @@
  * @{
  */
 
+/* These precompiler names were copied from chromium's build_config.h. */
+
+/*
+ * A set of macros to use for platform detection. These were largely copied
+ * from chromium's build_config.h.
+ */
+#if defined(__APPLE__)

[brettw, 2011/12/01 18:29:22]

It doesn't seem like all this code should be at the "api" level. NaCl compiles
Pepper for multiple platforms, and the API should be platform-agnostic,
shouldn't it? And none of these defines look like the're used in the c/cpp
layers.

If we need them in the tests, can we move it there?

[dmichael (off chromium), 2011/12/01 18:40:53]

Good point. Done.

+#define PPAPI_OS_MACOSX 1
+#elif defined(ANDROID)
+#define PPAPI_OS_ANDROID 1
+#elif defined(__native_client__)
+#define PPAPI_OS_NACL 1
+#elif defined(__linux__)
+#define PPAPI_OS_LINUX 1
+#elif defined(_WIN32)
+#define PPAPI_OS_WIN 1
+#elif defined(__FreeBSD__)
+#define PPAPI_OS_FREEBSD 1
+#elif defined(__OpenBSD__)
+#define PPAPI_OS_OPENBSD 1
+#elif defined(__sun)
+#define PPAPI_OS_SOLARIS 1
+#else
+#error Please add support for your platform in ppapi/c/pp_macros.h.
+#endif
+
+/* These are used to determine POSIX-like implementations vs Windows. */
+#if defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) || \
+    defined(__OpenBSD__) || defined(__sun) || defined(__native_client__)
+#define PPAPI_POSIX 1
+#endif
+
 /* Use PP_INLINE to tell the compiler to inline functions.  The main purpose of
  * inline functions in ppapi is to allow us to define convenience functions in
  * the ppapi header files, without requiring clients or implementers to link a