Fix issues revealed by -ftrivial-auto-var-init=pattern

-ftrivial-auto-var-init=pattern automatically initializes all variables
with a pattern. This revealed two issues:

1. Unitialized read of field from CrashpadInfoClientOptions.
2. The PC distance check in TestCaptureContext (due to additional
instrumentation, the distance is now 76 on x86-64 and 92 on aarch64).

Change-Id: I528e5f21c70d2849c9300776da783fde59411e9e
Reviewed-on: https://chromium-review.googlesource.com/c/1471691
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Mark Mentovai <mark@chromium.org>

snapshot/crashpad_info_client_options.cc

@@ -39,7 +39,8 @@ TriState CrashpadInfoClientOptions::TriStateFromCrashpadInfo(
 CrashpadInfoClientOptions::CrashpadInfoClientOptions()
     : crashpad_handler_behavior(TriState::kUnset),
       system_crash_reporter_forwarding(TriState::kUnset),
-      gather_indirectly_referenced_memory(TriState::kUnset) {
+      gather_indirectly_referenced_memory(TriState::kUnset),
+      indirectly_referenced_memory_cap(0) {
 }
 
 }  // namespace crashpad

util/misc/capture_context_test.cc

@@ -55,7 +55,7 @@ void TestCaptureContext() {
   const uintptr_t kReferencePC =
       reinterpret_cast<uintptr_t>(TestCaptureContext);
   EXPECT_PRED2([](uintptr_t actual,
-                  uintptr_t reference) { return actual - reference < 64u; },
+                  uintptr_t reference) { return actual - reference < 128u; },
                pc,
                kReferencePC);
 #endif  // !defined(ADDRESS_SANITIZER)