[fuchsia] Make fuchsia.memorypressure.Provider disconnects fatal

This service is required.

Bug: 1094035
Change-Id: I9f13d02df4edcaa411b3c32dd9408594b5864586
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2255781
Auto-Submit: David Dorwin <ddorwin@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Commit-Queue: David Dorwin <ddorwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781935}

base/util/memory_pressure/system_memory_pressure_evaluator_fuchsia.cc

@@ -34,9 +34,7 @@ SystemMemoryPressureEvaluatorFuchsia::SystemMemoryPressureEvaluatorFuchsia(
     std::unique_ptr<util::MemoryPressureVoter> voter)
     : util::SystemMemoryPressureEvaluator(std::move(voter)), binding_(this) {
   binding_.set_error_handler([](zx_status_t status) {
-    // TODO(https://crbug.com/1020698): Update fuchsia.web docs to make this a
-    // required service, and make this a FATAL log.
-    ZX_LOG(WARNING, status) << "fuchsia.memorypressure.Provider disconnected.";
+    ZX_LOG(FATAL, status) << "fuchsia.memorypressure.Provider disconnected";
   });
 
   DVLOG(1) << "Registering for memory pressure updates.";

base/util/memory_pressure/system_memory_pressure_evaluator_fuchsia_unittest.cc

@@ -60,13 +60,18 @@ class SystemMemoryPressureEvaluatorFuchsiaTest
   fuchsia::memorypressure::WatcherPtr watcher_;
 };
 
-TEST_F(SystemMemoryPressureEvaluatorFuchsiaTest, ProviderUnavailable) {
+using SystemMemoryPressureEvaluatorFuchsiaDeathTest =
+    SystemMemoryPressureEvaluatorFuchsiaTest;
+
+TEST_F(SystemMemoryPressureEvaluatorFuchsiaDeathTest, ProviderUnavailable) {
   auto voter = std::make_unique<MockMemoryPressureVoter>();
   SystemMemoryPressureEvaluatorFuchsia evaluator(std::move(voter));
 
   // Spin the loop to allow the evaluator to notice that the Provider is not
-  // available, to verify that that doesn't trigger a fatal failure.
-  base::RunLoop().RunUntilIdle();
+  // available and verify that this causes a fatal failure.
+  ASSERT_DEATH(base::RunLoop().RunUntilIdle(),
+               "fuchsia\\.memorypressure\\.Provider disconnected: "
+               "ZX_ERR_PEER_CLOSED \\(-24\\)");
 }
 
 TEST_F(SystemMemoryPressureEvaluatorFuchsiaTest, Basic) {

build/config/fuchsia/gfx_tests.cmx

@@ -15,6 +15,7 @@
       "fuchsia.intl.PropertyProvider",
       "fuchsia.logger.Log",
       "fuchsia.logger.LogSink",
+      "fuchsia.memorypressure.Provider",
       "fuchsia.process.Launcher",
       "fuchsia.sys.Environment",
       "fuchsia.sys.Loader",

fuchsia/engine/OWNERS

@@ -10,3 +10,5 @@ per-file web_engine_browser_interface_binders.*=file://ipc/SECURITY_OWNERS
 # For sandbox security review.
 per-file context_provider_impl.*=set noparent
 per-file context_provider_impl.*=file://fuchsia/SECURITY_OWNERS
+per-file *.cmx=set noparent
+per-file *.cmx=file://fuchsia/SECURITY_OWNERS

fuchsia/engine/web_engine_integration_tests.cmx

@@ -13,6 +13,7 @@
       "fuchsia.logger.LogSink",
       "fuchsia.media.Audio",
       "fuchsia.media.SessionAudioConsumerFactory",
+      "fuchsia.memorypressure.Provider",
       "fuchsia.net.NameLookup",
       "fuchsia.netstack.Netstack",
       "fuchsia.posix.socket.Provider",