1Multiple repo Chromium trybots 2============================== 3 4When a proposed Skia change will require a change in Chromium or Blink it is 5often helpful to locally create the Chromium and Blink changes and test with the 6proposed Skia change. This often happens with Skia API changes and changes 7which affect Blink layout tests. While simple to do locally, this explains how 8to do so on the Chromium trybots. 9 10Skia only changes 11----------------- 12If the Skia patch is already in Gerrit and there are no associated Chromium 13changes, then it is possible to just run the Chromium trybots. This will apply 14the Skia patch and run the bot. 15 16Skia and Chromium changes 17------------------------- 18If the Skia patch is already in Gerrit and there are associated Chromium 19changes, then in the Chromium CL add the following to 20\<chromium>/src/DEPS in the 'hooks' array. 21 22 { 23 'name': 'fetch_custom_patch', 24 'pattern': '.', 25 'action': [ 'git', '-C', 'src/third_party/skia/', 26 'fetch', 'https://skia.googlesource.com/skia', 'refs/changes/13/10513/13', 27 ], 28 }, 29 { 30 'name': 'apply_custom_patch', 31 'pattern': '.', 32 'action': ['git', '-C', 'src/third_party/skia/', 33 'cherry-pick', 'FETCH_HEAD', 34 ], 35 }, 36 37Modify the 'refs/changes/XX/YYYY/ZZ' to the appropriate values (where YYYY is 38the numeric change number, ZZ is the patch set number and XX is the last two 39digits of the numeric change number). This can be seen in the 'Download' link on 40Gerrit. 41 42If this is for a project other than Skia, update the checkout directory and 43fetch source. Note that this can be used multiple times to apply multiple 44issues. 45 46An example of this being used can be seen at 47https://crrev.com/2786433004/#ps1 . 48 49To test locally, run `gclient runhooks` to update the Skia source code. 50Note that if your local skia patch in `third_party/skia` isn't clean (e.g., you 51already applied some patch to it), then `gclient runhooks` won't successfully 52run. In that case, run `git reset --hard` inside `third_party/skia` before 53`gclient runhooks`. 54 55Arbitrary changes 56----------------- 57If the patch is to files where the above is not possible, then it is still 58possible to patch the files manually by adding the following to 59\<chromium>/src/DEPS in the 'hooks' array just before the 'gyp' hook. 60 61 { 62 'name': 'apply_custom_patch', 63 'pattern': '.', 64 'action': ['python', 65 '-c', 'from distutils.dir_util import copy_tree; copy_tree("src/patch/", "src/");' 66 ], 67 }, 68 69Then, copy all 'out of tree' files into \<chromium>/src/patch/, using the same 70directory structure used by Chromium. When 'gclient runhooks' is run, the files 71in \<chromium>/src/patch/ will be copied to and overwrite corresponding files in 72\<chromium>/src/. For example, if changing \<skia>/include/core/SkPath.h, place 73a copy of the modified SkPath.h at 74\<chromium>/src/patch/third_party/skia/include/core/SkPath.h. 75 76An example of this being used can be seen at 77https://crrev.com/1866773002/#ps20001 . 78 79 80Try the patch 81------------- 82After committing a \<chromium>/src/DEPS or \<chromium>/src/patch/ change 83locally, 'git cl upload' can be used in the usual way. Be sure to add 84'COMMIT=false' to the issue description to avoid accidentally checking it in. 85