Don't assume output dir + "../.." == src/ in ui/gl/generate_bindings.py

With gn, it'll probably be common for folks to generate their out directory
in places other than out/{Debug|Release}. This is technically possible (and
busted) in gyp as well. This avoids the relative path dependency from the
script and simplifies it some more by adding the src/ui/gl and src/gpu
directories in the build files (where they can be relativized properly)
instead of trying to do so in the script.

R=brettw@chromium.org

Review URL: https://codereview.chromium.org/317813002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@275520 0039d316-1c4b-4281-b951-d872f2087c98

ui/gl/BUILD.gn

@@ -293,7 +293,9 @@ action("generate_gl_bindings") {
   args = [
     "--header-paths=" +
         rebase_path("//third_party/khronos", root_build_dir) + ":" +
-        rebase_path("//third_party/mesa/src/include", root_build_dir),
+        rebase_path("//third_party/mesa/src/include", root_build_dir) + ":" +
+        rebase_path("//ui/gl", root_build_dir) + ":" +
+        rebase_path("//gpu", root_build_dir),
     rebase_path(gl_binding_output_dir, root_build_dir),
   ]
 }

ui/gl/generate_bindings.py

@@ -1963,17 +1963,10 @@ def FillExtensionsFromHeaders(functions, extension_headers, extra_extensions):
 def ResolveHeader(header, header_paths):
   paths = header_paths.split(':')
 
-  # Always use a path for Chromium-specific extensions. They are extracted
-  # to separate files.
-  paths.append('.')
-  paths.append('../../gpu')
-
-  root = os.path.abspath(os.path.dirname(__file__))
-
   for path in paths:
     result = os.path.join(path, header)
     if not os.path.isabs(path):
-      result = os.path.relpath(os.path.join(root, result), os.getcwd())
+      result = os.path.relpath(os.path.join(os.getcwd(), result), os.getcwd())
     if os.path.exists(result):
       # Always use forward slashes as path separators. Otherwise backslashes
       # may be incorrectly interpreted as escape characters.

ui/gl/gl.gyp

@@ -136,7 +136,7 @@
           'variables': {
             'generator_path': 'generate_bindings.py',
             # Prefer khronos EGL/GLES headers by listing that path first.
-            'header_paths': '../../third_party/khronos:../../third_party/mesa/src/include',
+            'header_paths': '../../third_party/khronos:../../third_party/mesa/src/include:.:../../gpu',
           },
           'inputs': [
             '<(generator_path)',