Zero initialize MemoryPressureVoteAggregator's vote list.

Add zero-initialization of the MemoryPressureVoteAggregator's list of
votes. Also moves initialization of it's |current_pressure_level_| to
the header file.

Bug: 980965
Change-Id: I75ed6f7ff50d0b680f55e8df93c981761fe5a843
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773705Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
Commit-Queue: Ryan Powell <ryanpow@google.com>
Cr-Commit-Position: refs/heads/master@{#691638}

base/util/memory_pressure/memory_pressure_voter.cc

@@ -11,10 +11,7 @@
 namespace util {
 
 MemoryPressureVoteAggregator::MemoryPressureVoteAggregator(Delegate* delegate)
-    : current_pressure_level_(
-          base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE),
-      delegate_(delegate),
-      votes_() {}
+    : delegate_(delegate) {}
 
 MemoryPressureVoteAggregator::~MemoryPressureVoteAggregator() {
   DCHECK_EQ(std::accumulate(votes_.begin(), votes_.end(), 0), 0);

base/util/memory_pressure/memory_pressure_voter.h

@@ -59,7 +59,8 @@ class MemoryPressureVoteAggregator {
   // MemoryPressureLevel.
   MemoryPressureLevel EvaluateVotes() const;
 
-  MemoryPressureLevel current_pressure_level_;
+  MemoryPressureLevel current_pressure_level_ =
+      base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE;
 
   Delegate* const delegate_;
 
@@ -72,7 +73,7 @@ class MemoryPressureVoteAggregator {
   // MemoryPressureLevel system will be changing soon regardless.
   std::array<size_t,
              base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL + 1>
-      votes_;
+      votes_ = {};
 
   SEQUENCE_CHECKER(sequence_checker_);