Memory-infra: Whitelist download service provider

BUG=791205

Change-Id: I13e256c1876d6c0ce7e3dc3044bce716666d01e5
Reviewed-on: https://chromium-review.googlesource.com/922889Reviewed-by: Xing Liu <xingliu@chromium.org>
Commit-Queue: Siddhartha S <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537219}

base/trace_event/memory_infra_background_whitelist.cc

@@ -24,6 +24,7 @@ const char* const kDumpProviderWhitelist[] = {
     "BlinkObjectCounters",
     "ClientDiscardableSharedMemoryManager",
     "DOMStorage",
+    "DownloadService",
     "DiscardableSharedMemoryManager",
     "gpu::BufferManager",
     "gpu::RenderbufferManager",
@@ -88,6 +89,7 @@ const char* const kAllocatorDumpNameWhitelist[] = {
     "blink_objects/V8PerContextData",
     "blink_objects/WorkerGlobalScope",
     "blink_objects/UACSSResource",
+    "components/download/controller_0x?",
     "discardable",
     "discardable/child_0x?",
     "extensions/value_store/Extensions.Database.Open.Settings/0x?",