Fix shared image memory dump

Both gpu/shared-images/* and gpu/shared_images/* are used as the memory
dump name for shared images. Other GPU code uses an underscore in dump
names so use gpu/shared_images.

Bug: none
Change-Id: I03466b6ca43cd4d35e5227804d7de1125b3ac865
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1894465
Auto-Submit: kylechar <kylechar@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711925}

gpu/command_buffer/service/shared_image_manager.cc

@@ -294,7 +294,7 @@ void SharedImageManager::OnMemoryDump(const Mailbox& mailbox,
 
   // Unique name in the process.
   std::string dump_name =
-      base::StringPrintf("gpu/shared-images/client_0x%" PRIX32 "/mailbox_%s",
+      base::StringPrintf("gpu/shared_images/client_0x%" PRIX32 "/mailbox_%s",
                          client_id, mailbox.ToDebugString().c_str());
 
   base::trace_event::MemoryAllocatorDump* dump =