Update SpareRenderProcessHostManager to use RPHI::InSameStoragePartition().

Replaces StoragePartition pointer comparisons with InSameStoragePartition()
so that it matches what is in RPHI::IsSuitableHost() and
RPHI::GetProcessHostForSiteInstance(). There is no behavior change here.

Bug: 1015882
Change-Id: Ia574b299bd484e146f5135b1c4d34bd6541342ba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2347390
Commit-Queue: Nasko Oskov <nasko@chromium.org>
Auto-Submit: Aaron Colwell <acolwell@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796636}

content/browser/renderer_host/render_process_host_impl.cc

@@ -605,7 +605,7 @@ class SpareRenderProcessHostManager : public RenderProcessHostObserver {
       action = SpareProcessMaybeTakeAction::kNoSparePresent;
     else if (browser_context != spare_render_process_host_->GetBrowserContext())
       action = SpareProcessMaybeTakeAction::kMismatchedBrowserContext;
-    else if (site_storage != spare_render_process_host_->GetStoragePartition())
+    else if (!spare_render_process_host_->InSameStoragePartition(site_storage))
       action = SpareProcessMaybeTakeAction::kMismatchedStoragePartition;
     else if (!embedder_allows_spare_usage)
       action = SpareProcessMaybeTakeAction::kRefusedByEmbedder;
@@ -620,7 +620,7 @@ class SpareRenderProcessHostManager : public RenderProcessHostObserver {
     RenderProcessHost* returned_process = nullptr;
     if (spare_render_process_host_ &&
         browser_context == spare_render_process_host_->GetBrowserContext() &&
-        site_storage == spare_render_process_host_->GetStoragePartition() &&
+        spare_render_process_host_->InSameStoragePartition(site_storage) &&
         !site_instance->IsGuest() && embedder_allows_spare_usage &&
         site_instance_allows_spare_usage) {
       CHECK(spare_render_process_host_->HostHasNotBeenUsed());