Change toolchain-major to pick up gcc-4_9-mobile branch.
Change toolchain-major to pick up gcc-4_9-mobile branch.

CQ-DEPEND=CL:182398
BUG=None
TEST=None

Change-Id: I019bb3ed151f28a8a1c3c7a0ac40e66e3461ac87
Reviewed-on: https://chromium-review.googlesource.com/182412
Reviewed-by: Luis Lozano <b1b2d032e61ab81482ec067b4d64feefa7d5de96@chromium.org>
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Commit-Queue: Han Shen <025253d3aa95f32ae4a9bb41f0f6bed72b33d2ce@chromium.org>
Tested-by: Han Shen <025253d3aa95f32ae4a9bb41f0f6bed72b33d2ce@chromium.org>

chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite