[ios] Remove the unused ios_automatically_manage_certs flag.

Bug: 994873
Change-Id: I814dbb66c22efda67c31f0827c3f1f251ae263bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1394435
Reviewed-by: Rohit Rao <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Commit-Queue: Justin Cohen <[email protected]>
Auto-Submit: Justin Cohen <[email protected]>
Cr-Commit-Position: refs/heads/master@{#687924}
diff --git a/docs/ios/build_instructions.md b/docs/ios/build_instructions.md
index 547a6b5e..4fb5b123 100644
--- a/docs/ios/build_instructions.md
+++ b/docs/ios/build_instructions.md
@@ -154,17 +154,7 @@
 
 ### Mobile provisioning profiles for tests
 
-In addition to that, you need provisioning profiles for the individual test
-suites that you want to run. Their bundle identifier depends on whether the
-gn variable `ios_automatically_manage_certs` is set to true (the default)
-or false.
-
-If set to true, then you just need a provisioning profile for the bundle
-identifier `${prefix}.gtest.generic-unit-test` but you can only have a
-single test application installed on the device (all the test application
-will share the same bundle identifier).
-
-If set to false, then you need a different provisioning profile for each
+In addition to that, you need a different provisioning profile for each
 test application. Those provisioning profile will have a bundle identifier
 matching the following pattern `${prefix}.gtest.${test-suite-name}` where
 `${test-suite-name}` is the name of the test suite with underscores changed
@@ -178,10 +168,8 @@
 -   `${prefix}.test.EarlGrey`
 
 In addition to that, then you'll need one additional provisioning profile for
-the XCTest module too. This module bundle identifier depends on whether the
-gn variable `ios_automatically_manage_certs` is set to true or false. If set
-to true, then `${prefix}.gtest.generic-unit-test-module` will be used, otherwise
-it will match the pattern: `${prefix}.gtest.${test-suite-name}-module`.
+the XCTest module too. It must match the pattern:
+`${prefix}.gtest.${test-suite-name}-module`.
 
 ### Other applications