Upstream web js bundle.

ios/web/js_compile.gypi

Index: ios/web/js_compile.gypi
diff --git a/ios/web/js_compile.gypi b/ios/web/js_compile.gypi
index b5212b5357b32344e05e2c6772a8827a76463ce8..df195544151809a8c03250bbf5bc347c954998b8 100644
--- a/ios/web/js_compile.gypi
+++ b/ios/web/js_compile.gypi
@@ -3,19 +3,51 @@
 # found in the LICENSE file.
 
 {
-  # TODO(ios): Enable javascript compilation. See http://crbug.com/429756
-  'rules': [
-    {
-      'rule_name': 'jscompilation',
-      'extension': 'js',
-      'outputs': [
-        '<(SHARED_INTERMEDIATE_DIR)/<(RULE_INPUT_NAME)',
-      ],
-      'action': [
-        'cp',
-        '<(RULE_INPUT_PATH)',
-        '<@(_outputs)',
-      ],
-    },
-  ],  # rule_name: jscompilation
+  'variables': {
+    'closure_compiler_path': '<(DEPTH)/third_party/closure_compiler/compiler/compiler.jar',
+    'compile_javascript%': 1,
+  },
+  'conditions': [
+    ['compile_javascript==1', {
+      'rules': [
+        {
+          'rule_name': 'jscompilation',
+          'extension': 'js',
+          'inputs': [
+            '<(closure_compiler_path)',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/<(RULE_INPUT_NAME)',
+          ],
+          'action': [
+            'java',
+            '-jar',
+            '<(closure_compiler_path)',
+            '--compilation_level',
+            'SIMPLE_OPTIMIZATIONS',
+            '--js',
+            '<(RULE_INPUT_PATH)',
+            '--js_output_file',
+            '<@(_outputs)',
+          ],
+          'message': 'Running closure compiler on <(RULE_INPUT_NAME)',
+        }  # rule_name: jscompilation
+      ]},
+     {  # else
+      'rules': [
+        {
+          'rule_name': 'jscompilation',
+          'extension': 'js',
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/<(RULE_INPUT_NAME)',
+          ],
+          'action': [
+            'cp',
+            '<(RULE_INPUT_PATH)',
+            '<@(_outputs)',
+          ],
+        }
+      ]}  # rule_name: jscompilation
+    ]  # condition: compile_javascript
+  ]  # conditions
 }