Improve formatting of accessibility tests that dump the tree.

content/browser/accessibility/dump_accessibility_tree_helper.h

Index: content/browser/accessibility/dump_accessibility_tree_helper.h
diff --git a/content/browser/accessibility/dump_accessibility_tree_helper.h b/content/browser/accessibility/dump_accessibility_tree_helper.h
index 90332068ef97168ff1d4dc2721aaa9b1b22d5c8e..314ef7419256d5234d2e7af2ab379be3959e3f4a 100644
--- a/content/browser/accessibility/dump_accessibility_tree_helper.h
+++ b/content/browser/accessibility/dump_accessibility_tree_helper.h
@@ -11,15 +11,13 @@
 #include "content/browser/accessibility/browser_accessibility.h"
 
 // A utility class for retrieving platform specific accessibility information.
+// This is extended by a subclass for each platform where accessibility is
+// implemented.
 class DumpAccessibilityTreeHelper {
  public:
   // Dumps a BrowserAccessibility tree into a string.
   void DumpAccessibilityTree(BrowserAccessibility* node,
-                             string16* contents) {
-    *contents += ToString(node) + GetLineEnding();
-    for (size_t i = 0; i < node->children().size(); ++i)
-      DumpAccessibilityTree(node->children()[i], contents);
-  }
+                             string16* contents);
 
   // Suffix of the expectation file corresponding to html file.
   // Example:
@@ -29,12 +27,15 @@ class DumpAccessibilityTreeHelper {
   const FilePath::StringType GetActualFileSuffix() const;
   const FilePath::StringType GetExpectedFileSuffix() const;
 
-  // Line ending to use in our dump.
-  const string16 GetLineEnding() const;
-
  protected:
+  void RecursiveDumpAccessibilityTree(BrowserAccessibility* node,
+                                      string16* contents,
+                                      int indent);
+
   // Returns a platform specific representation of a BrowserAccessibility.
-  string16 ToString(BrowserAccessibility* node);
+  // Should be zero or more complete lines, each with |prefix| prepended
+  // (to indent each line).
+  string16 ToString(BrowserAccessibility* node, char* prefix);
 
   void Initialize();
 };