Fix download controller memory dump provider

GetOrCreate dump is only used when the provider is not certain if the
dump should be created. Multiple dumps should have unique IDs.

BUG=791205

Change-Id: I46dec025517fb22f0b62a12d7e3ae64c45aa333a
Reviewed-on: https://chromium-review.googlesource.com/892488
Commit-Queue: Siddhartha S <ssid@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533591}

components/download/internal/background_service/controller_impl.cc

@@ -4,6 +4,8 @@
 
 #include "components/download/internal/background_service/controller_impl.h"
 
+#include <inttypes.h>
+
 #include <string>
 #include <vector>
 
@@ -11,6 +13,7 @@
 #include "base/callback_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/optional.h"
+#include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/memory_allocator_dump.h"
 #include "base/trace_event/memory_dump_manager.h"
@@ -597,7 +600,9 @@ base::Optional<LogSource::EntryDetails> ControllerImpl::GetServiceDownload(
 
 bool ControllerImpl::OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                                   base::trace_event::ProcessMemoryDump* pmd) {
-  auto* dump = pmd->GetOrCreateAllocatorDump("components/download");
+  auto* dump = pmd->CreateAllocatorDump(
+      base::StringPrintf("components/download/controller_0x%" PRIXPTR,
+                         reinterpret_cast<uintptr_t>(this)));
 
   size_t memory_cost =
       base::trace_event::EstimateMemoryUsage(externally_active_downloads_);