merged branch fabpot/profiler-tests (PR #4897)
merged branch fabpot/profiler-tests (PR #4897)

Commits
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22e9036 updated CHANGELOG
bafe890 [FrameworkBundle] changed Client::enableProfiler() behavior to fail silently when the profiler is not available (it makes it easier to write functional tests)
f41872b [FrameworkBundle] added a way to enable the profiler for the very next request in functional tests (closes #4307)
67b91e5 [HttpKernel] added a way to enable a disable Profiler

Discussion
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[2.2] added a way to enable the profiler for the very next request in a functional test

Bug fix: yes/no
Feature addition: yes
Backwards compatibility break: no
Symfony2 tests pass: yes
Fixes the following tickets: #4307
Todo: -
License of the code: MIT
Documentation PR: should be done before merging

After merging this PR, we need to disable the profiler in the test environment in Symfony SE.

symfony/HttpKernel,symfony/http-kernel