PartitionAllocator: relax condition that skips test on lowmem devices

Some of the exclusions introduced by crrev.com/2618853002 to deal
with OOM flakiness on lowmem devices are too aggressive and were
already dealt with by crrev.com/2589813002 .
Effectively this is a partial revert of crrev.com/2618853002 .

BUG=675255

Review-Url: https://codereview.chromium.org/2616063002
Cr-Commit-Position: refs/heads/master@{#442075}

base/allocator/partition_allocator/partition_alloc_unittest.cc

@@ -611,12 +611,6 @@ TEST(PartitionAllocTest, GenericAlloc) {
 // Test the generic allocation functions can handle some specific sizes of
 // interest.
 TEST(PartitionAllocTest, GenericAllocSizes) {
-  // TODO(crbug.com/678782): Where necessary and possible, disable the
-  // platform's OOM-killing behavior. OOM-killing makes this test flaky on
-  // low-memory devices.
-  if (!IsLargeMemoryDevice())
-    return;
-
   TestSetup();
 
   void* ptr = partitionAllocGeneric(genericAllocator.root(), 0, typeName);
@@ -714,12 +708,6 @@ TEST(PartitionAllocTest, GenericAllocSizes) {
 
 // Test that we can fetch the real allocated size after an allocation.
 TEST(PartitionAllocTest, GenericAllocGetSize) {
-  // TODO(crbug.com/678782): Where necessary and possible, disable the
-  // platform's OOM-killing behavior. OOM-killing makes this test flaky on
-  // low-memory devices.
-  if (!IsLargeMemoryDevice())
-    return;
-
   TestSetup();
 
   void* ptr;
@@ -1281,8 +1269,10 @@ static void DoReturnNullTest(size_t allocSize) {
   // TODO(crbug.com/678782): Where necessary and possible, disable the
   // platform's OOM-killing behavior. OOM-killing makes this test flaky on
   // low-memory devices.
-  if (!IsLargeMemoryDevice())
+  if (!IsLargeMemoryDevice()) {
+    LOG(WARNING) << "Skipping test on this device because of crbug.com/678782";
     return;
+  }
 
   TestSetup();