Fix leaks in exensions_unittests after enabling Oilpan

This CL adds an Oilpan's GC before tearing down the extensions_unittests.

BUG=581092

Review URL: https://codereview.chromium.org/1632763003

Cr-Commit-Position: refs/heads/master@{#371408}

extensions/renderer/module_system_test.cc

@@ -22,6 +22,7 @@
 #include "extensions/renderer/object_backed_native_handler.h"
 #include "extensions/renderer/safe_builtins.h"
 #include "extensions/renderer/utils_native_handler.h"
+#include "third_party/WebKit/public/web/WebHeap.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace extensions {
@@ -240,6 +241,7 @@ void ModuleSystemTest::TearDown() {
     old_heap_size = stats.used_heap_size();
     isolate_->RequestGarbageCollectionForTesting(
         v8::Isolate::kFullGarbageCollection);
+    blink::WebHeap::collectAllGarbageForTesting();
     isolate_->GetHeapStatistics(&stats);
   }
 }

tools/valgrind/memcheck/suppressions.txt

@@ -3405,31 +3405,3 @@
    fun:_ZN2cc10GLRenderer18DrawRenderPassQuadEPNS_14DirectRenderer12DrawingFrameEPKNS_18RenderPassDrawQuadEPKN3gfx5QuadFE
    fun:_ZN2cc10GLRenderer10DoDrawQuadEPNS_14DirectRenderer12DrawingFrameEPKNS_8DrawQuadEPKN3gfx5QuadFE
 }
-{
-   bug_581092_a
-   Memcheck:Leak
-   ...
-   fun:_ZN5blink15ContextFeatures13defaultSwitchEv
-   fun:_ZN5blink8DocumentC2ERKNS_12DocumentInitEh
-   fun:_ZN5blink12HTMLDocumentC1ERKNS_12DocumentInitEh
-   fun:_ZN5blink12HTMLDocument6createERKNS_12DocumentInitE
-   fun:_ZN5blink17DOMImplementation14createDocumentERKN3WTF6StringERKNS_12DocumentInitEb
-   fun:_ZN5blink14LocalDOMWindow14createDocumentERKN3WTF6StringERKNS_12DocumentInitEb
-   fun:_ZN5blink14LocalDOMWindow18installNewDocumentERKN3WTF6StringERKNS_12DocumentInitEb
-   fun:_ZN5blink14DocumentLoader15createWriterForEPKNS_*
-}
-{
-   bug_581092_b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN5blink26RefCountedGarbageCollectedINS_15StyleFilterDataEE13makeKeepAliveEv
-   fun:_ZN5blink26RefCountedGarbageCollectedINS_15StyleFilterDataEE3refEv
-   ...
-   fun:_ZN5blink7DataRefINS_15StyleFilterDataEE4initEv
-   ...
-   fun:_ZN5blink13ComputedStyle6createEv
-   fun:_ZN5blink13StyleResolver16styleForDocumentERNS_8DocumentE
-   fun:_ZN5blink8Document6attachERKNS_4Node13AttachContextE
-   fun:_ZN5blink14LocalDOMWindow18installNewDocumentERKN3WTF6StringERKNS_12DocumentInitEb
-   fun:_ZN5blink14DocumentLoader15createWriterForEPKNS_*
-}