Allow the asan_coverage GYP flag to accept arbitrary values.

build/common.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 335 matching lines @@
       # If this is set, the clang plugins used on the buildbot will be used.
       # Run tools/clang/scripts/update.sh to make sure they are compiled.
       # This causes 'clang_chrome_plugins_flags' to be set.
       # Has no effect if 'clang' is not set as well.
       'clang_use_chrome_plugins%': 1,
 
       # Enable building with ASAN (Clang's -fsanitize=address option).
       # -fsanitize=address only works with clang, but asan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/addresssanitizer
       'asan%': 0,
-      # Enable coverage gathering instrumentation in ASan.
+      # Enable coverage gathering instrumentation in ASan. This flag also
+      # controls coverage granularity (experimental).
       'asan_coverage%': 0,
 
       # Enable building with LSan (Clang's -fsanitize=leak option).
       # -fsanitize=leak only works with clang, but lsan=1 implies clang=1
       # See https://sites.google.com/a/chromium.org/dev/developers/testing/leaksanitizer
       'lsan%': 0,
 
       # Enable building with TSAN (Clang's -fsanitize=thread option).
       # -fsanitize=thread only works with clang, but tsan=1 implies clang=1
       # See http://clang.llvm.org/docs/ThreadSanitizer.html
@@ skipping 3082 matching lines @@
                 ],
                 'ldflags': [
                   '-fsanitize=address',
                 ],
                 'defines': [
                   'ADDRESS_SANITIZER',
                 ],
               }],
             ],
           }],
-          ['asan_coverage==1', {
+          ['asan_coverage!=0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
-                  '-mllvm -asan-coverage=1',
+                  '-mllvm -asan-coverage=<(asan_coverage)',
                 ],
               }],
             ],
           }],
           ['lsan==1', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
                   '-fsanitize=leak',
                 ],
@@ skipping 639 matching lines @@
               'OTHER_CFLAGS': [
                 '-fsanitize=address',
                 '-w',  # http://crbug.com/162783
               ],
             },
             'defines': [
               'ADDRESS_SANITIZER',
               'MEMORY_TOOL_REPLACES_ALLOCATOR',
             ],
           }],
-          ['asan_coverage==1', {
+          ['asan_coverage!=0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags': [
-                  '-mllvm -asan-coverage=1',
+                  '-mllvm -asan-coverage=<(asan_coverage)',
                 ],
               }],
             ],
           }],
         ],
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
             'conditions': [
               ['asan==1', {
@@ skipping 699 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }