Disable linux_aura on the main builders.

ppapi/native_client/tests/breakpad_crash_test/nacl.scons

Index: ppapi/native_client/tests/breakpad_crash_test/nacl.scons
diff --git a/ppapi/native_client/tests/breakpad_crash_test/nacl.scons b/ppapi/native_client/tests/breakpad_crash_test/nacl.scons
index 64900721487079b72fd85160ea9ccd67a8eab5ca..f3ce99a0a58df783999a593bedaee1b04a481a4b 100644
--- a/ppapi/native_client/tests/breakpad_crash_test/nacl.scons
+++ b/ppapi/native_client/tests/breakpad_crash_test/nacl.scons
@@ -83,13 +83,8 @@ env.AddNodeToTestSuite(
     node, ['chrome_browser_tests'], 'run_breakpad_crash_in_syscall_test',
     # This test is currently flaky on Win 32 bit on x86, disabling there.
     # See bug: https://code.google.com/p/chromium/issues/detail?id=254583
-    #
-    # These tests are also disabled on linux_aura, pending debugging of why the
-    # GPU process crashes. piman@ thinks it may be a simple flags issue.
-    # See bug: https://code.google.com/p/chromium/issues/detail?id=303342
     is_broken=env.PPAPIBrowserTesterIsBroken() or
                env.Bit('running_on_valgrind') or
-               env.Bit('host_linux') or
                (env.Bit('host_windows') and env.Bit('build_x86_32')))
 
 # Crashes in untrusted code should not produce crash dumps.
@@ -103,10 +98,5 @@ node = env.PPAPIBrowserTester(
     args=platform_args + ['--expected_crash_dumps=0'])
 env.AddNodeToTestSuite(
     node, ['chrome_browser_tests'], 'run_breakpad_untrusted_crash_test',
-    # This currently reliably fails in linux_aura configurations, probably for
-    # the same reasons that the previous test fails.
-    #
-    # See bug: https://code.google.com/p/chromium/issues/detail?id=303342
     is_broken=env.PPAPIBrowserTesterIsBroken() or
-               env.Bit('running_on_valgrind') or
-               env.Bit('host_linux'))
+               env.Bit('running_on_valgrind'))