Initialize memory, remove valgrind supression, add transparency test.

tools/valgrind/memcheck/suppressions.txt

 # There are four 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 # running overnight and removing outdated bugs/suppressions.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 6196 matching lines @@
    bug_166470d
    Memcheck:Leak
    ...
    fun:_ZN7fileapi26GetOriginIdentifierFromURLERK4GURL
    fun:_ZN11dom_storage14DomStorageArea26DatabaseFileNameFromOriginERK4GURL
    fun:_ZN11dom_storage14DomStorageAreaC1ERK4GURLRK8FilePathPNS_20DomStorageTaskRunnerE
    fun:_ZN11dom_storage19DomStorageNamespace24DeleteLocalStorageOriginERK4GURL
    fun:_ZN11dom_storage17DomStorageContext18DeleteLocalStorageERK4GURL
 }
 {
-   bug_166584
-   Memcheck:Uninitialized
-   fun:_ZN7testing8internal11CmpHelperEQIjjEENS_15AssertionResultEPKcS4_RKT_RKT0_
-   fun:_ZN7testing8internal8EqHelperILb0EE7CompareIjjEENS_15AssertionResultEPKcS6_RKT_RKT0_
-   fun:_ZN39SkBitmapOperationsTest_RotateImage_Test8TestBodyEv
-}
-{
    bug_166709
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN4base4BindIMNS_12_GLOBAL__N_121PostTaskAndReplyRelayEFvvENS_8internal17UnretainedWrapper*
    fun:_ZN4base8internal20PostTaskAndReplyImpl16PostTaskAndReplyERKN15tracked_objects8Location*
    ...
    fun:_ZN16ExtensionService12AddExtensionEPKN10extensions9ExtensionE
    fun:_ZN52BackgroundApplicationListModelTest_ExplicitTest_Test8TestBodyEv
 }
 {
@@ skipping 331 matching lines @@
    fun:_ZN7WebCore18RenderLayerBacking13updateFiltersEPKNS_11RenderStyleE
    fun:_ZN7WebCore18RenderLayerBacking*GraphicsLayer*
 }
 {
    bug_173356
    Memcheck:Overlap
    fun:memcpy
    fun:_ZN3gpu5gles2*Immediate4InitE*
    fun:_ZN3gpu5gles2*GLES2ImplementationTest_*_Test8TestBodyEv
 }