Enable BUILD file compilation of skia and dm with --config=android_arm.

tools/flags/SkCommandLineFlags.cpp

Index: tools/flags/SkCommandLineFlags.cpp
diff --git a/tools/flags/SkCommandLineFlags.cpp b/tools/flags/SkCommandLineFlags.cpp
index fe3dfd193d08bf171ab0ecbabed141292c519ede..8120ecc5e302a4a6cef900472ed2174c387482f2 100644
--- a/tools/flags/SkCommandLineFlags.cpp
+++ b/tools/flags/SkCommandLineFlags.cpp
@@ -11,7 +11,12 @@
 
 #include <stdlib.h>
 
+#if defined(GOOGLE3) && defined(SK_BUILD_FOR_ANDROID)
+// I don't know why, but this is defined by //base only for Android.
+DECLARE_bool(undefok)

[mtklein, 2015/10/20 17:48:55]

.... wow, this works?  That's a huge surprise.  Presumably, in this case we're
hopping onto a gflags undefok bool*.  That's sort of unexpectedly convenient.

It'd be nice to indent these DECLARE_ 4 spaces inside the #if.

[dogben, 2015/10/20 22:21:03]

s/convenient/inconvenient/, since whether it's defined depends on the platform.
:-/

+#else
 DEFINE_bool(undefok, false, "Silently ignore unknown flags instead of crashing.");
+#endif
 
 template <typename T> static void ignore_result(const T&) {}