Bug 1607697 - Box the memory reports in enums. r=Gankro

Clippy warns against it being much larger than the other enum variants.

Differential Revision: https://phabricator.services.mozilla.com/D59117

[wrupdater] From https://hg.mozilla.org/mozilla-central/rev/921c9f58037bf7c0c89b7c45c3f8a94f50b5814f

webrender/src/scene_builder_thread.rs

@@ -144,7 +144,7 @@ pub enum SceneBuilderRequest {
     SimulateLongSceneBuild(u32),
     SimulateLongLowPrioritySceneBuild(u32),
     Stop,
-    ReportMemory(MemoryReport, MsgSender<MemoryReport>),
+    ReportMemory(Box<MemoryReport>, MsgSender<Box<MemoryReport>>),
     #[cfg(feature = "capture")]
     SaveScene(CaptureConfig),
     #[cfg(feature = "replay")]
@@ -362,7 +362,7 @@ impl SceneBuilderThread {
                     break;
                 }
                 Ok(SceneBuilderRequest::ReportMemory(mut report, tx)) => {
-                    report += self.report_memory();
+                    (*report) += self.report_memory();
                     tx.send(report).unwrap();
                 }
                 Ok(SceneBuilderRequest::SimulateLongSceneBuild(time_ms)) => {

webrender_api/src/api.rs

@@ -1009,7 +1009,7 @@ pub enum ApiMsg {
     /// Flush from the caches anything that isn't necessary, to free some memory.
     MemoryPressure,
     /// Collects a memory report.
-    ReportMemory(MsgSender<MemoryReport>),
+    ReportMemory(MsgSender<Box<MemoryReport>>),
     /// Change debugging options.
     DebugCommand(DebugCommand),
     /// Wakes the render backend's event loop up. Needed when an event is communicated
@@ -1538,7 +1538,7 @@ impl RenderApi {
     pub fn report_memory(&self) -> MemoryReport {
         let (tx, rx) = channel::msg_channel().unwrap();
         self.api_sender.send(ApiMsg::ReportMemory(tx)).unwrap();
-        rx.recv().unwrap()
+        *rx.recv().unwrap()
     }
 
     /// Update debugging flags.