Reland #2: Improve mocking of os_path.exists() in PRESUBMIT_test.py

This reverts commit 58cf9bbd1611e4a9107fa98f18fbf55a212c0850.

Reason for reland: Fixed broken test

Original change's description:
> Revert "Reland "Improve mocking of os_path.exists() in PRESUBMIT_test.py""
>
> This reverts commit 3ba398ee581a391ccca563c57ffe52ee914fa7c9.
>
> Reason for revert: crbug.com/372313790
>
> Original change's description:
> > Reland "Improve mocking of os_path.exists() in PRESUBMIT_test.py"
> >
> > This reverts commit 74e5e087cb103dfe499aa9c1a41c4ccbba328da7.
> >
> > Reason for reland: Fixed blink & webapk presubmit tests
> >
> > Original change's description:
> > > Revert "Improve mocking of os_path.exists() in PRESUBMIT_test.py"
> > >
> > > This reverts commit b35a9a9465f6fc8cc200f559047f93e75d504806.
> > >
> > > Reason for revert: Manual bisect shows that this is responsible for failures starting in https://ci.chromium.org/ui/p/chromium/builders/ci/linux-presubmit/19822/blamelist.  Local repro on Linux: `vpython3 chrome/android/webapk/PRESUBMIT_test.py --verbose`
> > >
> > > Original change's description:
> > > > Improve mocking of os_path.exists() in PRESUBMIT_test.py
> > > >
> > > > I need this for an upcoming change, but it turns out it found 2 real
> > > > bugs:
> > > >  * A .pydeps check that would never be hit due to test mocks returning
> > > >    that deleted files exist
> > > >  * A translations check that would never be hit due to test mocks using
> > > >    local paths when absolute paths were requested.
> > > >
> > > > Bug: None
> > > > Change-Id: I920e4f67b2ff1193b89c7abfd9664d14a94c44bf
> > > > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5910106
> > > > Reviewed-by: Ted Choc <[email protected]>
> > > > Commit-Queue: Andrew Grieve <[email protected]>
> > > > Cr-Commit-Position: refs/heads/main@{#1364918}
> > >
> > > Bug: None
> > > Change-Id: Ibcc1931e5709d1a4209e56211595df8b94a35c9a
> > > No-Presubmit: true
> > > No-Tree-Checks: true
> > > No-Try: true
> > > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5913697
> > > Reviewed-by: Andrew Grieve <[email protected]>
> > > Bot-Commit: Rubber Stamper <[email protected]>
> > > Auto-Submit: Łukasz Anforowicz <[email protected]>
> > > Owners-Override: Łukasz Anforowicz <[email protected]>
> > > Commit-Queue: Łukasz Anforowicz <[email protected]>
> > > Cr-Commit-Position: refs/heads/main@{#1364999}
> >
> > Bug: None
> > Change-Id: I303d4d1abc685e3bad854e9a5ebe8ae2efe48869
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5912982
> > Commit-Queue: Andrew Grieve <[email protected]>
> > Auto-Submit: Andrew Grieve <[email protected]>
> > Reviewed-by: Ted Choc <[email protected]>
> > Owners-Override: Andrew Grieve <[email protected]>
> > Cr-Commit-Position: refs/heads/main@{#1365664}
>
> Bug: None
> Change-Id: Iaebc98243a14fff08442948fea4d69531f6103ee
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5918609
> Commit-Queue: Rubber Stamper <[email protected]>
> Owners-Override: Sophey Dong <[email protected]>
> Bot-Commit: Rubber Stamper <[email protected]>
> Auto-Submit: Sophey Dong <[email protected]>
> Cr-Commit-Position: refs/heads/main@{#1365901}

Bug: None
Change-Id: I998b8bea9e513d24652ce3d92bf88f677c987538
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5921545
Commit-Queue: Andrew Grieve <[email protected]>
Reviewed-by: Ted Choc <[email protected]>
Owners-Override: Andrew Grieve <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1368995}
diff --git a/chrome/browser/PRESUBMIT_test.py b/chrome/browser/PRESUBMIT_test.py
index 17a0d16c..c3a195a 100755
--- a/chrome/browser/PRESUBMIT_test.py
+++ b/chrome/browser/PRESUBMIT_test.py
@@ -22,11 +22,7 @@
 class BlinkPublicWebUnwantedDependenciesTest(unittest.TestCase):
   def makeInputApi(self, files):
     input_api = MockInputApi()
-    input_api.files = files
-    # Override os_path.exists because the presubmit uses the actual
-    # os.path.exists.
-    input_api.CreateMockFileInPath(
-        [x.LocalPath() for x in input_api.AffectedFiles(include_deletes=True)])
+    input_api.InitFiles(files)
     return input_api
 
   INVALID_DEPS_MESSAGE = ('chrome/browser cannot depend on '