binding: Introduces ExceptionToPromiseScope.

third_party/WebKit/Source/bindings/scripts/utilities.py

Index: third_party/WebKit/Source/bindings/scripts/utilities.py
diff --git a/third_party/WebKit/Source/bindings/scripts/utilities.py b/third_party/WebKit/Source/bindings/scripts/utilities.py
index 2d812434f9be78697ee4a71d9e49fde892635fba..697ec8731c14eb21c7526fa63061659a7c841e44 100644
--- a/third_party/WebKit/Source/bindings/scripts/utilities.py
+++ b/third_party/WebKit/Source/bindings/scripts/utilities.py
@@ -407,6 +407,43 @@ def shorten_union_name(union_type):
     return name
 
 
+def format_remove_duplicates(text, patterns):
+    """Removes duplicated line-basis patterns.
+
+    Based on simple pattern matching, removes duplicated lines in a block
+    of lines.  Lines that match with a same pattern are considered as
+    duplicates.
+
+    Designed to be used as a filter function for Jinja2.
+
+    Args:
+        text: A str of multi-line text.
+        patterns: A list of str where each str represents a simple
+            pattern.  The patterns are not considered as regexp, and
+            exact match is applied.
+
+    Returns:
+        A formatted str with duplicates removed.
+    """
+    pattern_founds = [False] * len(patterns)
+    output = []
+    for line in text.split('\n'):
+        for i, pattern in enumerate(patterns):
+            if pattern not in line:
+                continue
+            if pattern_founds[i]:
+                line = ''
+            else:
+                pattern_founds[i] = True
+        output.append(line)
+
+    # Let |'\n'.join| emit the last newline.
+    if output:
+        output.append('')
+
+    return '\n'.join(output)
+
+
 def format_blink_cpp_source_code(text):
     """Formats C++ source code.