Address leaks in Linux accessibility tree tests

1. Unref AtkStateSet and AtkRelationSet when we're finished with them.

2. For atk_table_get_column_description and _row_description, we're
dynamically generating a value but the API appears to expect us to
return a static string. For now I've scoped the existing LSAN disabling
down to include just this spot since all remaining leaks are fixed.

Bug: 568674
Change-Id: I7174312452ae118eacb706cd7e686bf8649a790f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1688317
Commit-Queue: Kevin Babbitt <kbabbitt@microsoft.com>
Reviewed-by: Martin Robinson <mrobinson@igalia.com>
Cr-Commit-Position: refs/heads/master@{#676103}

content/browser/accessibility/accessibility_event_recorder_auralinux.cc

@@ -276,6 +276,7 @@ void AccessibilityEventRecorderAuraLinux::ProcessATKEvent(
   states = base::CollapseWhitespaceASCII(states, false);
   base::ReplaceChars(states, " ", ",", &states);
   log += base::StringPrintf(" %s", states.c_str());
+  g_object_unref(state_set);
 
   OnEvent(log);
 }

content/browser/accessibility/accessibility_tree_formatter_auralinux.cc

@@ -509,6 +509,7 @@ void AccessibilityTreeFormatterAuraLinux::AddProperties(
       states->AppendString(atk_state_type_get_name(state_type));
   }
   dict->Set("states", std::move(states));
+  g_object_unref(state_set);
 
   AtkRelationSet* relation_set = atk_object_ref_relation_set(atk_object);
   auto relations = std::make_unique<base::ListValue>();
@@ -518,6 +519,7 @@ void AccessibilityTreeFormatterAuraLinux::AddProperties(
       relations->AppendString(atk_relation_type_get_name(relation_type));
   }
   dict->Set("relations", std::move(relations));
+  g_object_unref(relation_set);
 
   AtkAttributeSet* attributes = atk_object_get_attributes(atk_object);
   for (AtkAttributeSet* attr = attributes; attr; attr = attr->next) {

content/browser/accessibility/dump_accessibility_browsertest_base.h

@@ -8,10 +8,8 @@
 #include <string>
 #include <vector>
 
-#include "base/debug/leak_annotations.h"
 #include "base/strings/string16.h"
 #include "base/test/scoped_feature_list.h"
-#include "build/build_config.h"
 #include "content/browser/accessibility/accessibility_event_recorder.h"
 #include "content/public/browser/accessibility_tree_formatter.h"
 #include "content/public/test/content_browser_test.h"
@@ -112,11 +110,6 @@ class DumpAccessibilityTestBase : public ContentBrowserTest,
   // The node filters loaded from the test file.
   std::vector<AccessibilityTreeFormatter::NodeFilter> node_filters_;
 
-#if defined(LEAK_SANITIZER) && !defined(OS_NACL)
-  // http://crbug.com/568674
-  ScopedLeakSanitizerDisabler lsan_disabler;
-#endif
-
   // The current tree-formatter and event-recorder factories.
   AccessibilityTreeFormatter::FormatterFactory formatter_factory_;
   AccessibilityEventRecorder::EventRecorderFactory event_recorder_factory_;

ui/accessibility/platform/ax_platform_node_auralinux.cc

@@ -15,6 +15,7 @@
 #include <vector>
 
 #include "base/command_line.h"
+#include "base/debug/leak_annotations.h"
 #include "base/no_destructor.h"
 #include "base/optional.h"
 #include "base/strings/string_number_conversions.h"
@@ -23,6 +24,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversion_utils.h"
 #include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
 #include "ui/accessibility/ax_action_data.h"
 #include "ui/accessibility/ax_mode_observer.h"
 #include "ui/accessibility/ax_node_data.h"
@@ -285,6 +287,16 @@ const char* BuildDescriptionFromHeaders(AXPlatformNodeDelegate* delegate,
   }
 
   std::string result = base::JoinString(names, " ");
+
+#if defined(LEAK_SANITIZER) && !defined(OS_NACL)
+  // http://crbug.com/982839
+  // atk_table_get_column_description and atk_table_get_row_description return
+  // const gchar*, which suggests the caller does not gain ownership of the
+  // returned string. The g_strdup below causes a new allocation, which does not
+  // fit that pattern and causes a leak in tests.
+  ScopedLeakSanitizerDisabler lsan_disabler;
+#endif
+
   return g_strdup(result.c_str());
 }