[android] Update to Robolectric 3.4.2.

With Robolectric 3.4.2, we can nearly run vanilla, only requiring
the following modifications:
 - we need to have a stub impl of MavenDependencyResolver since there
   is no point to adding the third-party Maven jars to Chromium.
 - we need to have some files which are generated by Robolectric
   annotation processor during compile time. GN makes it
   difficult to use these auto-gen files during the build.

This also rolls findbugs to pick up a GN change required to expose a
JAR for 3.4.2.

Bug: 729135
Change-Id: I3e80b532bd88ba6a40b64eb935a31f52cc20588f
Reviewed-on: https://chromium-review.googlesource.com/709469
Commit-Queue: John Budorick <[email protected]>
Reviewed-by: Miguel Casas <[email protected]>
Reviewed-by: Bernhard Bauer <[email protected]>
Reviewed-by: Tommy Nyquist <[email protected]>
Reviewed-by: Changwan Ryu <[email protected]>
Reviewed-by: agrieve <[email protected]>
Cr-Commit-Position: refs/heads/master@{#515606}
diff --git a/DEPS b/DEPS
index 8f4f4723..5fbcffc 100644
--- a/DEPS
+++ b/DEPS
@@ -333,7 +333,7 @@
     Var('chromium_git') + '/chromium/third_party/ffmpeg.git' + '@' + 'c99db0ab53a43f09e65caf0b546c8a4b19a36f60',
 
   'src/third_party/findbugs': {
-      'url': Var('chromium_git') + '/chromium/deps/findbugs.git' + '@' + '57f05238d3ac77ea0a194813d3065dd780c6e566',
+      'url': Var('chromium_git') + '/chromium/deps/findbugs.git' + '@' + '4275d9ac8610db6b1bc9a5e887f97e41b33fac67',
       'condition': 'checkout_android',
   },
 
@@ -566,7 +566,7 @@
   },
 
   'src/third_party/robolectric/robolectric': {
-      'url': Var('chromium_git') + '/external/robolectric.git' + '@' + 'b02c65cc6d7465f58f0de48a39914aa905692afa',
+      'url': Var('chromium_git') + '/external/robolectric.git' + '@' + '4a3f2156ab7eb5213dffc3afe2d08b78dedb1478',
       'condition': 'checkout_android',
   },