Constellation can now optionally report memory usage when the page is loaded. (#37151)

The constellation can now tell the memory reporter to report the memory
to a trace file when a page is loaded.
Additionally, we amend the memory reporter to allow a simple message
where it will report the memory to a tracing provider (at the moment
only OHOS/hitrace is supported but easy extension is possible).

I am not sure if this is the right approach or if the embedder should
decide to have the memory reporting done.

Testing: This does not change functionality of any of the rendering.

---------

Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>

components/constellation/tracing.rs

@@ -78,6 +78,7 @@ mod from_compositor {
                 Self::SetScrollStates(..) => target!("SetScrollStates"),
                 Self::PaintMetric(..) => target!("PaintMetric"),
                 Self::EvaluateJavaScript(..) => target!("EvaluateJavaScript"),
+                Self::CreateMemoryReport(..) => target!("CreateMemoryReport"),
             }
         }
     }