chore(profiling): make memory alloc profiler tests more end-to-end (#15330)

## Description

Previously, the tests directly tested the internal data-structures.
Modified the tests to instead create the actual pprof, then check its
data.
This provides more realistic testing.
It also is a first step to enabling changing the data-structures from
python to native.

## Testing

<!-- Describe your testing strategy or note what tests are included -->

## Risks

<!-- Note any risks associated with this change, or "None" if no risks
-->

## Additional Notes

<!-- Any other information that would be helpful for reviewers -->

---------

Co-authored-by: T. Kowalski <[email protected]>

Author: danielsn

ddtrace/profiling/collector/memalloc.py

@@ -3,6 +3,7 @@
 import os
 import threading
 from types import TracebackType
+from typing import Any
 from typing import List
 from typing import NamedTuple
 from typing import Optional
@@ -162,5 +163,36 @@ def test_snapshot(self) -> Tuple[MemorySample, ...]:
 
         return tuple(samples)
 
+    def snapshot_and_parse_pprof(self, output_filename: str) -> Any:
+        """Export samples to profile, upload, and parse the pprof profile.
+
+        This is similar to test_snapshot() but exports to the profile and returns
+        the parsed pprof profile instead of Python objects.
+
+        Args:
+            output_filename: The pprof output filename prefix (without .pid.counter suffix)
+
+        Returns:
+            Parsed pprof profile object (pprof_pb2.Profile)
+
+        Raises:
+            ImportError: If pprof_utils is not available (only available in test environment)
+        """
+        # Export samples to profile
+        self.snapshot()
+
+        # Upload to write profile to disk
+        ddup.upload()
+
+        # Parse the profile (only available in test environment)
+        try:
+            from tests.profiling.collector import pprof_utils
+        except ImportError:
+            raise ImportError(
+                "pprof_utils is not available. snapshot_and_parse_pprof() is only available in test environment."
+            )
+
+        return pprof_utils.parse_newest_profile(output_filename)
+
     def collect(self) -> Tuple[MemorySample, ...]:
         return tuple()

tests/profiling/collector/pprof_utils.py

@@ -204,7 +204,7 @@ def assert_lock_events_of_type(
     assert all(get_label_with_key(profile.string_table, sample, "lock name") for sample in samples), (
         "All samples should have the label 'lock name'"
     )
-    samples = {
+    samples_dict = {
         profile.string_table[
             cast(pprof_pb2.Label, get_label_with_key(profile.string_table, sample, "lock name")).str
         ]: sample
@@ -215,8 +215,8 @@ def assert_lock_events_of_type(
             key = "{}:{}".format(expected_event.filename, expected_event.linenos.create)
         else:
             key = "{}:{}:{}".format(expected_event.filename, expected_event.linenos.create, expected_event.lock_name)
-        assert key in samples, "Expected lock event {} not found".format(key)
-        assert_lock_event(profile, samples[key], expected_event)
+        assert key in samples_dict, "Expected lock event {} not found".format(key)
+        assert_lock_event(profile, samples_dict[key], expected_event)
 
 
 def assert_lock_events(