Move TrimWhitespace to the base namespace.

printing/backend/cups_helper.cc

Index: printing/backend/cups_helper.cc
diff --git a/printing/backend/cups_helper.cc b/printing/backend/cups_helper.cc
index 5636f089476e9549fc702d4e7dd5ab06d13f3198..6a0e220c801162ba1e39202fb1d3a80c68f51df2 100644
--- a/printing/backend/cups_helper.cc
+++ b/printing/backend/cups_helper.cc
@@ -62,7 +62,7 @@ void ParseLpOptions(const base::FilePath& filepath,
       continue;
     }
 
-    TrimWhitespaceASCII(line, TRIM_ALL, &line);
+    base::TrimWhitespaceASCII(line, base::TRIM_ALL, &line);
     if (line.empty())
       continue;
 
@@ -80,7 +80,8 @@ void ParseLpOptions(const base::FilePath& filepath,
     }
 
     line = line.substr(space_found + 1);
-    TrimWhitespaceASCII(line, TRIM_ALL, &line);  // Remove extra spaces.
+    // Remove extra spaces.
+    base::TrimWhitespaceASCII(line, base::TRIM_ALL, &line);
     if (line.empty())
       continue;
     // Parse the selected printer custom options.