Refactor suppression rules for Bug 90013.

This change updates suppression rules for Bug 90013 to remove unknown symbols as much as possible. We need to install more debug symbols, though.

TBR=thakis
BUG=90013
TEST=make the "Chromium OS Heapcheck" bot greener.
Review URL: https://chromiumcodereview.appspot.com/10140015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@133635 0039d316-1c4b-4281-b951-d872f2087c98

tools/heapcheck/suppressions.txt

@@ -1226,62 +1226,27 @@
    bug_90013_a
    Heapcheck:Leak
    fun:??
-   ...
-   fun:pango_fc_font*
-   ...
-   fun:gfx::RenderTextLinux::*
+   fun:gfx::RenderTextLinux::EnsureLayout
 }
 {
    bug_90013_b
    Heapcheck:Leak
-   ...
-   fun:??
-   fun:??
    fun:??
-   ...
-   fun:pango_fc_font_*
+   fun:gfx::RenderTextLinux::GetStringSize
 }
 {
    bug_90013_c
    Heapcheck:Leak
    fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   fun:??
+   fun:::FindBestMatchFontFamilyName
+   fun:PlatformFontPango
 }
 {
    bug_90013_d
    Heapcheck:Leak
    fun:??
-   fun:??
-   fun:??
-   fun:??
-   ...
-   fun:XML_ParseBuffer
-   fun:??
-   fun:??
-   fun:??
-   fun:??
-   ...
-   fun:PlatformFontPango
+   fun:gfx::GetPangoFontMetrics
+   fun:gfx::PlatformFontPango::InitPangoMetrics
 }
 {
    bug_91491