Add Android WebView Flag

Add Flag and new enum values for the RunThreadControllerTasksByBatches experiment. And modifying regular expression to accept exported features to generate constant name.

Bug: 1299950
Change-Id: Ic2c8f735d9ba384a5c982efdff6dc4c731e67ba0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3667686
Commit-Queue: Alex Attar <[email protected]>
Reviewed-by: Nate Fischer <[email protected]>
Reviewed-by: Andrew Grieve <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1009597}
diff --git a/build/android/gyp/java_cpp_features.py b/build/android/gyp/java_cpp_features.py
index 8e7c244..f93bd99 100755
--- a/build/android/gyp/java_cpp_features.py
+++ b/build/android/gyp/java_cpp_features.py
@@ -19,7 +19,8 @@
   # would parse as:
   #   ExtractConstantName() -> 'ConstantName'
   #   ExtractValue() -> '"StringNameOfTheFeature"'
-  FEATURE_RE = re.compile(r'\s*const (?:base::)?Feature\s+k(\w+)\s*(?:=\s*)?{')
+  FEATURE_RE = re.compile(
+      r'\s*const(?:\s+\w+_EXPORT)? (?:base::)?Feature\s+k(\w+)\s*(?:=\s*)?')
   VALUE_RE = re.compile(r'\s*("(?:\"|[^"])*")\s*,')
 
   def ExtractConstantName(self, line):