Generalize unexpected passes expectations module

Generalizes the expectations module of the unexpected pass finder code
by pulling out all the GPU-specific code into a GPU-specific
implementation that extends the base class.

Also does some general refactoring on the expectations module, as a
sizable portion of the code belonged in different modules.

Bug: 1222826
Change-Id: Id02668856253528c2806ef4c3f715023a14e57ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3011896
Reviewed-by: Dirk Pranke <[email protected]>
Commit-Queue: Brian Sheedy <[email protected]>
Cr-Commit-Position: refs/heads/master@{#901718}
diff --git a/testing/PRESUBMIT.py b/testing/PRESUBMIT.py
index d04a511..65f2d62 100644
--- a/testing/PRESUBMIT.py
+++ b/testing/PRESUBMIT.py
@@ -13,13 +13,8 @@
 
 def CommonChecks(input_api, output_api):
   testing_env = dict(input_api.environ)
-  # TODO(crbug.com/1222826): Remove this path addition once all GPU-specific
-  # code is pulled out of the common code.
-  gpu_path = input_api.os_path.join(
-      input_api.PresubmitLocalPath(), '..', 'content', 'test', 'gpu')
   testing_env.update({
-      'PYTHONPATH': input_api.os_path.pathsep.join(
-          [input_api.PresubmitLocalPath(), gpu_path]),
+      'PYTHONPATH': input_api.PresubmitLocalPath(),
       'PYTHONDONTWRITEBYTECODE': '1',
   })