Only print the id in Aura/Linux ax_dump_tree if it exists

Stop printing a bogus integer version of the id attribute for nodes. We
are already printing the string version of this attribute when it is
assigned, so removing this code should just make the output less noisy.

Bug: 909620
Change-Id: I0b2f08c99ae5e52a14483f27292c5aacd7e5eace
Reviewed-on: https://chromium-review.googlesource.com/c/1352362Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Martin Robinson <mrobinson@igalia.com>
Cr-Commit-Position: refs/heads/master@{#613029}

content/browser/accessibility/accessibility_tree_formatter_auralinux.cc

@@ -310,10 +310,6 @@ base::string16 AccessibilityTreeFormatterAuraLinux::ProcessTreeForOutput(
       WriteAttribute(false, state_value, &line);
   }
 
-  int id_value;
-  node.GetInteger("id", &id_value);
-  WriteAttribute(false, base::StringPrintf("id=%d", id_value), &line);
-
   for (const char* attribute_name : ATK_OBJECT_ATTRIBUTES) {
     std::string attribute_value;
     if (node.GetString(attribute_name, &attribute_value)) {