Could you please add the following alerts?

For all benchmarks that use memory metric (system_health.memory_mobile, system_health.memory_desktop, v8.browsing_mobile, v8.browsing_desktop):
- memory:chrome:renderer_processes:reported_by_chrome:v8:allocated_by_malloc_peak_size_max
- (after https://codereview.chromium.org/2204213002/ lands, I will ping this thread when it happens):
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:effective_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:code_space:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:code_space:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:code_space:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:large_object_space:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:large_object_space:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:large_object_space:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:large_object_space:effective_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:map_space:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:map_space:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:map_space:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:map_space:effective_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:new_space:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:new_space:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:new_space:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:new_space:effective_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:old_space:allocated_objects_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:old_space:allocated_objects_size_max
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:old_space:effective_size_avg
   - memory:chrome:renderer_processes:reported_by_chrome:v8:heap:old_space:effective_size_max

For  v8.browsing_mobile, v8.browsing_desktop:
- the standard memory metric alerts (i.e. ones used for system_health.memory_mobile, system_health.memory_desktop).
- v8-gc-full-mark-compactor_avg
- v8-gc-full-mark-compactor_max
- v8-gc-full-mark-compactor_sum
- v8-gc-incremental-finalize_avg
- v8-gc-incremental-finalize_max
- v8-gc-incremental-finalize_sum
- v8-gc-incremental-step_avg
- v8-gc-incremental-step_max
- v8-gc-incremental-step_sum
- v8-gc-memory-mark-compactor_avg
- v8-gc-memory-mark-compactor_max
- v8-gc-memory-mark-compactor_sum
- v8-gc-latency-mark-compactor_avg
- v8-gc-latency-mark-compactor_max
- v8-gc-latency-mark-compactor_sum
- v8-gc-scavenger_avg
- v8-gc-scavenger_max
- v8-gc-scavenger_sum
- v8-gc-total_avg
- v8-gc-total_max
- v8-gc-total_sum