[code coverage] Update doc references to clang_coverage recipe module

The clang_coverage recipe module was renamed to code_coverage in
https://chromium-review.googlesource.com/c/chromium/tools/build/+/1670914.
This CL updates the references at chromium/src side accordingly.

Bug: 977032
Change-Id: I2059b978cbc75d3f8621e7c14880ee6d40a92f85
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1669984
Commit-Queue: Yuke Liao <liaoyuke@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672657}

docs/testing/code_coverage.md

@@ -305,7 +305,7 @@ because of significant shared logic.
 
 The code used by the bots that generate the coverage data lives (among other
 places) in the
-[clang coverage recipe module](https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/clang_coverage/).
+[code coverage recipe module](https://chromium.googlesource.com/chromium/tools/build/+/master/scripts/slave/recipe_modules/code_coverage/).
 
 ### Why is coverage for X not reported or unreasonably low, even though there is a test for X?
 

tools/mb/mb_config.pyl

@@ -2281,7 +2281,7 @@
 
     # Used to pass the list of files to instrument for coverage to the compile
     # wrapper. See:
-    # https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/clang_coverage/api.py
+    # https://cs.chromium.org/chromium/build/scripts/slave/recipe_modules/code_coverage/api.py
     # and
     # https://cs.chromium.org/chromium/src/docs/clang_code_coverage_wrapper.md
     'partial_clang_instrumentation': {