ObserverList prints AddObserver stack traces in check_empty

Users of ObserverList often want to verify that the ObserverList is
empty on destruction, i.e. that all observers have unregistered
themselves - hence the check_empty template param. However, if some
observers remain, it's currently impossible to tell *which* observers
failed to unregister themselves.
This CL adds logic to print the stack trace of observer *registration*
for any observers that remain during destruction, for DCHECK-enabled
builds.

Bug: 1176498
Change-Id: I099a964e3ef01c07326422460c0688fa1f7d6815
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2704550
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#856766}
2 files changed
tree: e7bed8caabfb358e8054a821e12a483229d7d0d0
  1. .clang-format
  2. .clang-tidy
  3. .eslintrc.js
  4. .git-blame-ignore-revs
  5. .gitattributes
  6. .gitignore
  7. .gn
  8. .vpython
  9. .vpython3
  10. .yapfignore
  11. AUTHORS
  12. BUILD.gn
  13. CODE_OF_CONDUCT.md
  14. DEPS
  15. DIR_METADATA
  16. ENG_REVIEW_OWNERS
  17. LICENSE
  18. LICENSE.chromium_os
  19. OWNERS
  20. PRESUBMIT.py
  21. PRESUBMIT_test.py
  22. PRESUBMIT_test_mocks.py
  23. README.md
  24. WATCHLISTS
  25. android_webview/
  26. apps/
  27. ash/
  28. base/
  29. build/
  30. build_overrides/
  31. buildtools/
  32. cc/
  33. chrome/
  34. chromecast/
  35. chromeos/
  36. cloud_print/
  37. codelabs/
  38. codereview.settings
  39. components/
  40. content/
  41. courgette/
  42. crypto/
  43. dbus/
  44. device/
  45. docs/
  46. extensions/
  47. fuchsia/
  48. gin/
  49. google_apis/
  50. google_update/
  51. gpu/
  52. headless/
  53. infra/
  54. ios/
  55. ipc/
  56. jingle/
  57. media/
  58. mojo/
  59. native_client_sdk/
  60. net/
  61. pdf/
  62. ppapi/
  63. printing/
  64. remoting/
  65. rlz/
  66. sandbox/
  67. services/
  68. skia/
  69. sql/
  70. storage/
  71. styleguide/
  72. testing/
  73. third_party/
  74. tools/
  75. ui/
  76. url/
  77. weblayer/
README.md

Logo Chromium

Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all users to experience the web.

The project's web site is https://www.chromium.org.

To check out the source code locally, don't use git clone! Instead, follow the instructions on how to get the code.

Documentation in the source is rooted in docs/README.md.

Learn how to Get Around the Chromium Source Code Directory Structure .

For historical reasons, there are some small top level directories. Now the guidance is that new top level directories are for product (e.g. Chrome, Android WebView, Ash). Even if these products have multiple executables, the code should be in subdirectories of the product.