Set default cross compiler for ARM/linux builds.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 79b682e550f81ef655a09d2bf9c04b746016108b..74c2415357e7aeeee5db13c2375bbc70e2d1230b 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -5596,6 +5596,16 @@
         ['CXX.host', '<!(which g++)'],
       ],
     }],
+    ['OS=="linux" and target_arch=="arm" and host_arch!="arm" and chromeos==0 and clang==0', {
+      # Set default ARM cross compiling on linux.  These can be overridden
+      # using CC/CXX/etc environment variables.
+      'make_global_settings': [
+        ['CC', '<!(which arm-linux-gnueabihf-gcc)'],
+        ['CXX', '<!(which arm-linux-gnueabihf-g++)'],
+        ['CC.host', '<!(which gcc)'],
+        ['CXX.host', '<!(which g++)'],
+      ],
+    }],
 
     # TODO(yyanagisawa): supports GENERATOR==make
     #  make generator doesn't support CC_wrapper without CC