Implement the webdriver window sizing commands.

chrome/test/webdriver/webdriver_util.h

Index: chrome/test/webdriver/webdriver_util.h
diff --git a/chrome/test/webdriver/webdriver_util.h b/chrome/test/webdriver/webdriver_util.h
index 628623b3736415ca501956d2aaad8053fda9dd87..dfc0959dcc5b31ab8551264e75ab639647db8c5d 100644
--- a/chrome/test/webdriver/webdriver_util.h
+++ b/chrome/test/webdriver/webdriver_util.h
@@ -34,6 +34,9 @@ std::string JsonStringifyForDisplay(const base::Value* value);
 // Returns the string representation of the given type, for display purposes.
 const char* GetJsonTypeName(base::Value::Type type);
 
+// Converts the automation ID to a string.
+std::string AutomationIdToString(const AutomationId& id);
+
 // Converts the string to an automation ID and returns true on success.
 bool StringToAutomationId(const std::string& string_id, AutomationId* id);