For #8803: add StartupTimeline ping type and framework_start metrics.

app/metrics.yaml

@@ -1984,3 +1984,57 @@ addons:
     notification_emails:
       - fenix-core@mozilla.com
     expires: "2020-09-01"
+
+startup.timeline:
+  framework_start:
+    send_in_pings:
+      - startup-timeline
+    type: timespan
+    time_unit: nanosecond
+    description: >
+      The duration the Android framework takes to start before letting us run code in
+      `*Application.init`. This is calculated from `appInitTimestamp - processStartTimestamp`.
+      `processStartTimestamp` is derived from the clock tick time unit, which is expected to be
+      less granular than nanoseconds. Therefore, we convert and round our timestamps to clock ticks
+      before computing the difference and convert back to nanoseconds to report.
+
+      For debugging purposes, `clock_ticks_per_second`, which may vary between devices, is also
+      reported as a metric.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/8803
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/9788#issuecomment-610648980
+    notification_emails:
+      - perf-android-fe@mozilla.com
+      - mcomella@mozilla.com
+    expires: "2020-10-01"
+  framework_start_error:
+    send_in_pings:
+      - startup-timeline
+    type: boolean
+    description: >
+      An error when attempting to record `framework_start` - the application init timestamp returned
+      a negative value - which is likely indicative of a bug in the implementation.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/8803
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/9788#issuecomment-610648980
+    notification_emails:
+      - perf-android-fe@mozilla.com
+      - mcomella@mozilla.com
+    expires: "2020-10-01"
+  clock_ticks_per_second:
+    send_in_pings:
+      - startup-timeline
+    type: counter
+    description: >
+      The number of clock tick time units that occur in one second on this particular device. This
+      value is expected to be used in conjunction with the `framework_start` metric.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/8803
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/9788#issuecomment-610648980
+    notification_emails:
+      - perf-android-fe@mozilla.com
+      - mcomella@mozilla.com
+    expires: "2020-10-01"

app/pings.yaml

@@ -29,3 +29,19 @@ installation:
     - https://github.com/mozilla-mobile/fenix/pull/8074#issuecomment-586512202
   notification_emails:
     - fenix-core@mozilla.com
+
+startup-timeline:
+  description: >
+    This ping is intended to provide an understanding of startup performance.
+
+    The ping is intended to be captured by performance testing automation to report results
+    there, in addition to user telemetry. We place these metrics into their own ping in order
+    to isolate them and make this process easier.
+  include_client_id: false
+  bugs:
+    - https://github.com/mozilla-mobile/fenix/issues/8803
+  data_reviews:
+    - https://github.com/mozilla-mobile/fenix/pull/9788#issuecomment-610648980
+  notification_emails:
+    - perf-android-fe@mozilla.com
+    - esmyth@mozilla.com