Bug 1566366 - Test Streaming Telemetry r=janerik

This test _can_ run on non-Android if we reconfigure GetCurrentProduct in
TelemetryCommon to not have an #ifdef for Android.

Differential Revision: https://phabricator.services.mozilla.com/D38741

--HG--
extra : moz-landing-system : lando

toolkit/components/telemetry/Histograms.json

@@ -8934,6 +8934,18 @@
     "description": "a testing histogram; not meant to be touched",
     "record_into_store": ["main", "sync"]
   },
+  "TELEMETRY_TEST_STREAMING": {
+    "record_in_processes": ["main"],
+    "products": ["geckoview_streaming"],
+    "alert_emails": ["telemetry-client-dev@mozilla.com"],
+    "expires_in_version": "never",
+    "kind": "linear",
+    "low": 1,
+    "high": 2147483646,
+    "n_buckets": 10,
+    "bug_numbers": [1566366],
+    "description": "a testing histogram; not meant to be touched"
+  },
   "STARTUP_CRASH_DETECTED": {
     "record_in_processes": ["main", "content"],
     "products": ["firefox", "fennec", "geckoview"],

toolkit/components/telemetry/geckoview/gtest/TestGeckoViewStreaming.cpp

@@ -0,0 +1,55 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "TelemetryFixture.h"
+#include "streaming/GeckoViewStreamingTelemetry.h"
+
+using namespace mozilla;
+using namespace mozilla::Telemetry;
+using namespace TelemetryTestHelpers;
+using GeckoViewStreamingTelemetry::StreamingTelemetryDelegate;
+using ::testing::_;
+using ::testing::Eq;
+
+namespace {
+
+const char* kGeckoViewStreamingPref = "toolkit.telemetry.geckoview.streaming";
+const char* kBatchTimeoutPref = "toolkit.telemetry.geckoview.batchDurationMS";
+
+class MockDelegate final : public StreamingTelemetryDelegate {
+ public:
+  MOCK_METHOD2(ReceiveHistogramSamples,
+               void(const nsCString& aHistogramName,
+                    const nsTArray<uint32_t>& aSamples));
+};  // class MockDelegate
+
+TEST_F(TelemetryTestFixture, StreamingTelemetryStreamsHistogramSamples) {
+  NS_NAMED_LITERAL_CSTRING(kTestHgramName, "TELEMETRY_TEST_STREAMING");
+  const uint32_t kSampleOne = 401;
+  const uint32_t kSampleTwo = 2019;
+
+  nsTArray<uint32_t> samplesArray;
+  samplesArray.AppendElement(kSampleOne);
+  samplesArray.AppendElement(kSampleTwo);
+
+  auto md = MakeRefPtr<MockDelegate>();
+  EXPECT_CALL(*md, ReceiveHistogramSamples(Eq(kTestHgramName),
+                                           Eq(std::move(samplesArray))));
+  GeckoViewStreamingTelemetry::RegisterDelegate(md);
+
+  Preferences::SetBool(kGeckoViewStreamingPref, true);
+  Preferences::SetInt(kBatchTimeoutPref, 5000);
+
+  Telemetry::Accumulate(Telemetry::TELEMETRY_TEST_STREAMING, kSampleOne);
+  Preferences::SetInt(kBatchTimeoutPref, 0);
+  Telemetry::Accumulate(Telemetry::TELEMETRY_TEST_STREAMING, kSampleTwo);
+
+  // Clear the delegate so when the batch is done being sent it can be deleted.
+  GeckoViewStreamingTelemetry::RegisterDelegate(nullptr);
+}
+
+}  // namespace

toolkit/components/telemetry/geckoview/gtest/moz.build

@@ -20,6 +20,12 @@ UNIFIED_SOURCES = [
     'TestGeckoView.cpp',
 ]
 
+# GeckoView Streaming Telemetry is only available on Android.
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
+  UNIFIED_SOURCES += [
+    'TestGeckoViewStreaming.cpp',
+  ]
+
 # We need the following line otherwise including
 # "TelemetryHistogram.h" in tests will fail due to
 # missing headers.