Fix the toolkit_views gyp variable define mania.

This makes it so toolkit_views==1 is always true for views builds,
either on Windows or ChromeOS.

Three levels of nesting are needed for this chained conditional:
1) Set the default value of ChromeOS.
2) Depending on ChromeOS value, set the default value of toolkit_views.
3) Depending on toolkit_views value, set the rest of the build variables.

This should have no affect on the build, but will allow subsequent cleanup.

Review URL: http://codereview.chromium.org/1799002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@45639 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/build/common.gypi b/build/common.gypi
index 372ad35..163cf9ba 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -48,7 +48,24 @@
             'host_arch%': 'ia32',
           }],
         ],
+
+        # Whether we're building a ChromeOS build.  We set the initial
+        # value at this level of nesting so it's available for the
+        # toolkit_views test below.
+        'chromeos%': '0',
       },
+
+      # Set default value of toolkit_views on for Windows and Chrome OS.
+      # We set it at this level of nesting so the value is available for
+      # other conditionals below.
+      'conditions': [
+        ['OS=="win" or chromeos==1', {
+          'toolkit_views%': 1,
+        }, {
+          'toolkit_views%': 0,
+        }],
+      ],
+
       'host_arch%': '<(host_arch)',
 
       # Default architecture we're building for is the architecture we're
@@ -62,13 +79,8 @@
       'linux_chromium_dump_symbols%': 0,
       # Also see linux_strip_binary below.
 
-      # By default, Linux does not use views. To turn on views in Linux,
-      # set the variable GYP_DEFINES to "toolkit_views=1", or modify
-      # ~/.gyp/include.gypi .
-      'toolkit_views%': 0,
-
-      # Defaults to a desktop build, overridden via command line/env.
-      'chromeos%': 0,
+      # Copy conditionally-set chromeos variable out one scope.
+      'chromeos%': '<(chromeos)',
 
       # This variable tells WebCore.gyp and JavaScriptCore.gyp whether they are
       # are built under a chromium full build (1) or a webkit.org chromium