Fix memory leaks in BufferedDataSource, BufferedResourceLoader and SimpleDataSource unit tests.

tools/heapcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1055 matching lines @@
    Heapcheck:Leak
    fun:base::BaseTimer::Start
    fun:ReloadButtonGtk::OnClicked
    fun:ReloadButtonGtk::OnClickedThunk
    fun:g_closure_invoke
    fun:ReloadButtonGtkTest_*_Test::TestBody
    fun:testing::HandleExceptionsInMethodIfSupported
    fun:testing::Test::Run
 }
 {
-   bug_65664a
-   Heapcheck:Leak
-   fun:webkit_glue::BufferedResourceLoaderTest::Initialize
-   fun:webkit_glue::BufferedResourceLoaderTest*
-}
-{
-   bug_65664b
-   Heapcheck:Leak
-   fun:webkit_glue::BufferedDataSourceTest::InitializeDataSource
-   fun:webkit_glue::BufferedDataSourceTest*
-}
-{
-   bug_65664c
-   Heapcheck:Leak
-   fun:webkit_glue::SimpleDataSourceTest::InitializeDataSource
-   fun:webkit_glue::SimpleDataSourceTest*
-}
-{
-   bug_65664d
-   Heapcheck:Leak
-   fun:webkit_glue::SimpleDataSourceTest_InitializeData_Test::TestBody
-   fun:testing::HandleExceptionsInMethodIfSupported
-}
-{
    bug_65680a
    Heapcheck:Leak
    fun:remoting::ScreenRecorderTest_OneRecordCycle_Test::TestBody
    fun:testing::HandleExceptionsInMethodIfSupported
 }
 {
    bug_65680b
    Heapcheck:Leak
    fun:remoting::ScreenRecorder::DoSendVideoPacket
    fun:void DispatchToMethod
@@ skipping 103 matching lines @@
    bug_70327
    Heapcheck:Leak
    fun:g_malloc
    fun:gfx::CanvasSkia::SizeStringInt
    fun:gfx::PlatformFontGtk::GetStringWidth
    fun:gfx::Font::GetStringWidth
    fun:ui::ElideUrl
    fun:ui::::RunTest
    fun:ui::TextEliderTest_TestGeneralEliding_Test::TestBody
 }