Add unittest for updating mozc candidates.

tools/heapcheck/suppressions.txt

Index: tools/heapcheck/suppressions.txt
diff --git a/tools/heapcheck/suppressions.txt b/tools/heapcheck/suppressions.txt
index f9c490d52b2b2aebdcfd0113701c1bdf8f398c24..9372df764b38fad047c089d47cd76a8babd0bc26 100644
--- a/tools/heapcheck/suppressions.txt
+++ b/tools/heapcheck/suppressions.txt
@@ -1785,20 +1785,3 @@
    fun:AccessibilityEventRouterViewsTest::CreateWindowWithContents
    fun:AccessibilityEventRouterViewsTest_TestFocusNotification_Test::TestBody
 }
-{
-   bug_106850_a
-   Heapcheck:Leak
-   ...
-   fun:::DefaultFocusManagerFactory::CreateFocusManager
-   fun:views::FocusManagerFactory::Create
-   fun:views::Widget::OnNativeWidgetCreated
-   fun:views::NativeWidgetGtk::InitNativeWidget
-   fun:views::Widget::Init
-   fun:chromeos::input_method::CandidateWindowViewTest_MozcUpdateCandidateTest_Test::TestBody
-}
-{
-   bug_106850_b
-   Heapcheck:Leak
-   fun:views::Widget::Init
-   fun:chromeos::input_method::CandidateWindowViewTest_MozcUpdateCandidateTest_Test::TestBody
-}