Add tests for the Display operation of the mac notification bridge.

chrome/browser/DEPS

Index: chrome/browser/DEPS
diff --git a/chrome/browser/DEPS b/chrome/browser/DEPS
index ec8d855c1d9b9591f1ccc546fffe2d841be4fb1f..479fbbc1fc746a8c3cb9f1c23afb755ad55e110a 100644
--- a/chrome/browser/DEPS
+++ b/chrome/browser/DEPS
@@ -87,6 +87,8 @@ include_rules = [
   "+third_party/leveldatabase",
   "+third_party/libxml",
   "+third_party/mozilla",     # Mozilla interface headers.
+  "+third_party/ocmock/gtest_support.h",
+  "+third_party/ocmock/OCMock/OCMock.h",

[Nico, 2016/07/12 17:54:38]

why is this needed? we already have many files in c/b that use ocmock:
https://cs.chromium.org/search/?q=ocmock.h+file:chrome&sq=package:chromium&ty...
As far as I can tell, they don't allow this in subdirectory DEPS files.

[Miguel Garcia, 2016/07/13 14:05:16]

I looked a some of those results and all of them had a DEPS rule somewhere in
their path to allow OCMock explicitly. 
https://cs.chromium.org/chromium/src/chrome/browser/renderer_host/DEPS
https://cs.chromium.org/chromium/src/chrome/browser/ui/cocoa/DEPS
https://cs.chromium.org/chromium/src/ios/DEPS

Worth noting that if I revert this file I get a presubmit error as well

Running presubmit commit checks ...

** Presubmit ERRORS **
You added one or more #includes that violate checkdeps rules.
  chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
      Illegal include: "third_party/ocmock/OCMock/OCMock.h"
    Because of no rule applying. \
  chrome/browser/notifications/notification_platform_bridge_mac_unittest.mm
      Illegal include: "third_party/ocmock/gtest_support.h"
    Because of no rule applying.


Would you prefer if I added a new DEPS file in chrome/browser/notifications ?

   "+third_party/protobuf/src/google/protobuf",
   "+third_party/re2",
   "+third_party/smhasher",