mesa: Don't build mapi.h / mapi.c

We don't need them, and they unconditionally mark their functions as
__declspec(dllimport) in the header in a static library build, which
causes warnings on the clang/win bot.

BUG=82385
R=kbr@chromium.org

Review URL: https://codereview.chromium.org/478153002

Cr-Commit-Position: refs/heads/master@{#290207}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290207 0039d316-1c4b-4281-b951-d872f2087c98

third_party/mesa/BUILD.gn

@@ -257,8 +257,6 @@ static_library("mesa") {
     "$generated_src_dir/mesa/glapi_mapi_tmp_shared.h",
     "src/src/mapi/mapi/entry.c",
     "src/src/mapi/mapi/entry.h",
-    "src/src/mapi/mapi/mapi.c",
-    "src/src/mapi/mapi/mapi.h",
     "src/src/mapi/mapi/mapi_glapi.c",
     "src/src/mapi/mapi/stub.c",
     "src/src/mapi/mapi/stub.h",

third_party/mesa/README.chromium

@@ -50,3 +50,5 @@ Modifications made:
 
 - Porting to x64 Android. Remove redefinitions of log2 and log2f.
   https://codereview.chromium.org/216773005/
+
+- Excluded src/mapi/mapi/mapi.{h,c} from the build.

third_party/mesa/mesa.gyp

@@ -283,8 +283,6 @@
         '<(generated_src_dir)/mesa/glapi_mapi_tmp_shared.h',
         'src/src/mapi/mapi/entry.c',
         'src/src/mapi/mapi/entry.h',
-        'src/src/mapi/mapi/mapi.c',
-        'src/src/mapi/mapi/mapi.h',
         'src/src/mapi/mapi/mapi_glapi.c',
         'src/src/mapi/mapi/stub.c',
         'src/src/mapi/mapi/stub.h',