linux/android: Reenable util test, and enable snapshot test

107fb7631788 added the snapshot library as a dependency of
crashpad_util_test. Most of snapshot has not yet been ported to Linux or
Android. snapshot/capture_memory.cc only supports x86 and x86_64, and
will #error on other CPUs. We don’t build for other CPUs on Mac or
Windows, but we do for Android.

To make it easy to run crashpad_util_test on non-x86 again,
conditionally remove capture_memory.cc on Linux and Android.

crashpad_snapshot_test can be enabled for Linux and Android too by
disabling the CrashpadInfoClientOptions tests which require OS support.
There’s not much left in crashpad_snapshot_test currently for Linux
except for CPUContextX86 and ProcessSnapshotMinidump.EmptyFile, but both
pass.

Bug: crashpad:30
Change-Id: Ic19a79932072710c69a296bc0156cbe5656b8cb3
Reviewed-on: https://chromium-review.googlesource.com/549116
Reviewed-by: Joshua Peraza <jperaza@chromium.org>

snapshot/snapshot.gyp

@@ -130,6 +130,12 @@
             ],
           },
         }],
+        ['OS=="linux" or OS=="android"', {
+          'sources!': [
+            'capture_memory.cc',
+            'capture_memory.h',
+          ],
+        }],
       ]
     },
     {

snapshot/snapshot_test.gyp

@@ -107,6 +107,11 @@
             'crashpad_snapshot_test_image_reader_module',
           ],
         }],
+        ['OS=="linux" or OS=="android"', {
+          'sources!': [
+            'crashpad_info_client_options_test.cc',
+          ],
+        }],
       ],
     },
     {