Reland "[oilpan] Fix stack limit check for recursive tracing"

The limit was defined as ~0ul (unsigned long) which is unsigned 32bit on Windows
64bit and thus extended with 0 for uintptr_t. This results in bogus return of
StackFrameDepth::IsSafeToRecurse of true even though recursion might be disabled
due to stack pressure.

This reverts commit e5d92d31.

Tbr: haraken@chromium.org
Bug: chromium:798479
Change-Id: Id7a897af323e230e11c7a1417f383bc868f6fe05
Reviewed-on: https://chromium-review.googlesource.com/848896Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526738}

third_party/WebKit/Source/platform/heap/HeapTest.cpp

@@ -42,6 +42,7 @@
 #include "platform/heap/HeapTestUtilities.h"
 #include "platform/heap/SafePoint.h"
 #include "platform/heap/SelfKeepAlive.h"
+#include "platform/heap/StackFrameDepth.h"
 #include "platform/heap/ThreadState.h"
 #include "platform/heap/Visitor.h"
 #include "platform/testing/UnitTestHelpers.h"
@@ -6253,6 +6254,20 @@ TEST(HeapTest, StackGrowthDirection) {
   EXPECT_EQ(kGrowsTowardsLower, StackGrowthDirection());
 }
 
+TEST(HeapTest, StackFrameDepthDisabledByDefault) {
+  StackFrameDepth depth;
+  // Only allow recursion after explicitly enabling the stack limit.
+  EXPECT_FALSE(depth.IsSafeToRecurse());
+}
+
+TEST(HeapTest, StackFrameDepthEnable) {
+  StackFrameDepth depth;
+  StackFrameDepthScope scope(&depth);
+  // The scope may fail to enable recursion when the stack is close to the
+  // limit. In all other cases we should be able to safely recurse.
+  EXPECT_TRUE(depth.IsSafeToRecurse() || !depth.IsEnabled());
+}
+
 class TestMixinAllocationA : public GarbageCollected<TestMixinAllocationA>,
                              public GarbageCollectedMixin {
   USING_GARBAGE_COLLECTED_MIXIN(TestMixinAllocationA);

third_party/WebKit/Source/platform/heap/StackFrameDepth.h

@@ -77,7 +77,7 @@ class PLATFORM_EXPORT StackFrameDepth final {
   // The stack pointer is assumed to grow towards lower addresses;
   // |kMinimumStackLimit| then being the limit that a stack
   // pointer will always exceed.
-  static const uintptr_t kMinimumStackLimit = ~0ul;
+  static const uintptr_t kMinimumStackLimit = ~uintptr_t{0};
 
   static uintptr_t GetFallbackStackLimit();