Improve --help and usage message for roll_deps.py

Also, don't use assert for user error handling plus
some other general python cleanup.

NOPRESUBMIT=true (presubmit is broken)

Review URL: https://codereview.chromium.org/1091603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@294950 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed
tree: f89f3e4203411225685086b8a1fa50f5c7824e3d
  1. bootstrap/
  2. git-templates/
  3. git_utils/
  4. man/
  5. recipes/
  6. support/
  7. testing_support/
  8. tests/
  9. third_party/
  10. win_toolchain/
  11. zsh-goodies/
  12. .gitignore
  13. annotated_gclient.py
  14. apply_issue
  15. apply_issue.bat
  16. apply_issue.py
  17. auth.py
  18. breakpad.py
  19. checkout.py
  20. chrome-update-create-task.bat
  21. chrome-update.bat
  22. chrome-update.py
  23. clang-format
  24. clang-format.bat
  25. clang_format.py
  26. codereview.settings
  27. commit_queue.py
  28. cpplint.bat
  29. cpplint.py
  30. cpplint_chromium.py
  31. create-chromium-git-src
  32. create-ntfs-junction.c
  33. create-ntfs-junction.exe
  34. dart_format.py
  35. depot-tools-auth
  36. depot-tools-auth.bat
  37. depot-tools-auth.py
  38. download_from_google_storage
  39. download_from_google_storage.bat
  40. download_from_google_storage.py
  41. drover
  42. drover.bat
  43. drover.py
  44. fetch
  45. fetch.bat
  46. fetch.py
  47. fix_encoding.py
  48. gcl
  49. gcl.bat
  50. gcl.py
  51. gclient
  52. gclient-new-workdir.py
  53. gclient.bat
  54. gclient.py
  55. gclient_completion.sh
  56. gclient_scm.py
  57. gclient_utils.py
  58. gerrit_util.py
  59. git-auto-svn
  60. git-cache
  61. git-cherry-pick-upload
  62. git-cl
  63. git-cl-upload-hook
  64. git-crrev-parse
  65. git-crsync
  66. git-crup
  67. git-footers
  68. git-freeze
  69. git-gs
  70. git-lkgr
  71. git-map
  72. git-map-branches
  73. git-mark-merge-base
  74. git-nav-downstream
  75. git-nav-upstream
  76. git-new-branch
  77. git-number
  78. git-rebase-update
  79. git-rename-branch
  80. git-reparent-branch
  81. git-retry
  82. git-runhooks
  83. git-squash-branch
  84. git-thaw
  85. git-try
  86. git-upstream-diff
  87. git_auto_svn.py
  88. git_cache.py
  89. git_cherry_pick_upload.py
  90. git_cl.py
  91. git_common.py
  92. git_footers.py
  93. git_freezer.py
  94. git_map.py
  95. git_map_branches.py
  96. git_mark_merge_base.py
  97. git_nav_downstream.py
  98. git_new_branch.py
  99. git_number.py
  100. git_rebase_update.py
  101. git_rename_branch.py
  102. git_reparent_branch.py
  103. git_retry.py
  104. git_squash_branch.py
  105. git_try.py
  106. git_upstream_diff.py
  107. gn
  108. gn.bat
  109. gn.py
  110. gsutil.py
  111. hammer
  112. hammer.bat
  113. LICENSE
  114. my_activity.py
  115. my_reviews.py
  116. ninja
  117. ninja-linux32
  118. ninja-linux64
  119. ninja-mac
  120. ninja.exe
  121. OWNERS
  122. owners.py
  123. owners_finder.py
  124. patch.py
  125. PRESUBMIT.py
  126. presubmit_canned_checks.py
  127. presubmit_support.py
  128. profile.xml
  129. pylint
  130. pylint.py
  131. pylintrc
  132. python_git_runner.sh
  133. README
  134. README.codereview
  135. README.gclient
  136. README.git-cl
  137. README.testing
  138. repo
  139. rietveld.py
  140. roll-dep
  141. roll-dep.bat
  142. roll_dep.py
  143. scm.py
  144. subcommand.py
  145. subprocess2.py
  146. trychange.py
  147. update_depot_tools
  148. update_depot_tools.bat
  149. upload_to_google_storage.py
  150. WATCHLISTS
  151. watchlists.py
  152. weekly
  153. wtf