Add sccache option to bootstrap (#12582)

* Add sccache option to bootstrap

Couldn't see a CC wrapper style option for gyp so we inject the sccache commands directly into the generated ninja files.

* Use CC_wrapper

* Update toolchain.gypi

* s/sccache/cc_wrapper

script/bootstrap.py

@@ -110,6 +110,8 @@ def parse_args():
                       help='The static library path of libchromiumcontent.')
   parser.add_argument('--defines', default='',
                       help='The build variables passed to gyp')
+  parser.add_argument('--cc_wrapper',
+                      help='Sets cc_wrapper for build. E.g. $(which sccache)')
   return parser.parse_args()
 
 
@@ -120,6 +122,8 @@ def args_to_defines(args):
   if args.clang_dir:
     defines += ' make_clang_dir=' + args.clang_dir
     defines += ' clang_use_chrome_plugins=0'
+  if args.cc_wrapper is not None:
+    defines += ' cc_wrapper=' + args.cc_wrapper
   return defines
 
 

toolchain.gypi

@@ -5,6 +5,9 @@
     # Set this to true when building with Clang.
     'clang%': 1,
 
+    # Set this to the absolute path to sccache when building with sccache
+    'cc_wrapper%': '',
+
     # Path to mips64el toolchain.
     'make_mips64_dir%': 'vendor/gcc-4.8.3-d197-n64-loongson/usr',
 
@@ -101,6 +104,15 @@
     ],
   },
   'conditions': [
+    # Setup cc_wrapper
+    ['cc_wrapper!=""', {
+      'make_global_settings': [
+        ['CC_wrapper', '<(cc_wrapper)'],
+        ['CXX_wrapper', '<(cc_wrapper)'],
+        ['CC.host_wrapper', '<(cc_wrapper)'],
+        ['CXX.host_wrapper', '<(cc_wrapper)']
+      ],
+    }],
     # Setup building with clang.
     ['clang==1', {
       'make_global_settings': [