Revert of [runtime] temporarily transform IsContext check from DHECK to CHECK...

Revert of [runtime] temporarily transform IsContext check from DHECK to CHECK (patchset #2 id:20001 of https://codereview.chromium.org/2164633002/ )

Reason for revert:
There have been no more occurrences of this on dev / beta so we can convert the CHECK back to DCHECK.

Original issue's description:
> [runtime] temporarily transform IsContext check from DCHECK to CHECK
>
> We are enabling this trial on canary to see if we can flush out some missing
> context restores.
>
> BUG=
>
> Committed: https://crrev.com/ec94ad400dc257af396efa3b1899bc3168347d82
> Cr-Commit-Position: refs/heads/master@{#37875}

TBR=jkummerow@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

Review-Url: https://codereview.chromium.org/2303543003
Cr-Commit-Position: refs/heads/master@{#39292}

src/arguments.h

@@ -81,7 +81,6 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
 
 // TODO(cbruni): add global flag to check whether any tracing events have been
 // enabled.
-// TODO(cbruni): Convert the IsContext CHECK back to a DCHECK.
 #define RUNTIME_FUNCTION_RETURNS_TYPE(Type, Name)                             \
   static INLINE(Type __RT_impl_##Name(Arguments args, Isolate* isolate));     \
                                                                               \
@@ -95,7 +94,7 @@ double ClobberDoubleRegisters(double x1, double x2, double x3, double x4);
   }                                                                           \
                                                                               \
   Type Name(int args_length, Object** args_object, Isolate* isolate) {        \
-    CHECK(isolate->context() == nullptr || isolate->context()->IsContext());  \
+    DCHECK(isolate->context() == nullptr || isolate->context()->IsContext()); \
     CLOBBER_DOUBLE_REGISTERS();                                               \
     if (V8_UNLIKELY(TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED() ||       \
                     FLAG_runtime_call_stats)) {                               \

src/builtins/builtins-utils.h

@@ -76,32 +76,31 @@ class BuiltinArguments : public Arguments {
 // through the BuiltinArguments object args.
 // TODO(cbruni): add global flag to check whether any tracing events have been
 // enabled.
-// TODO(cbruni): Convert the IsContext CHECK back to a DCHECK.
-#define BUILTIN(name)                                                        \
-  MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,  \
-                                                     Isolate* isolate);      \
-                                                                             \
-  V8_NOINLINE static Object* Builtin_Impl_Stats_##name(                      \
-      int args_length, Object** args_object, Isolate* isolate) {             \
-    BuiltinArguments args(args_length, args_object);                         \
-    RuntimeCallTimerScope timer(isolate, &RuntimeCallStats::Builtin_##name); \
-    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                    \
-                 "V8.Builtin_" #name);                                       \
-    return Builtin_Impl_##name(args, isolate);                               \
-  }                                                                          \
-                                                                             \
-  MUST_USE_RESULT Object* Builtin_##name(                                    \
-      int args_length, Object** args_object, Isolate* isolate) {             \
-    CHECK(isolate->context() == nullptr || isolate->context()->IsContext()); \
-    if (V8_UNLIKELY(TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED() ||      \
-                    FLAG_runtime_call_stats)) {                              \
-      return Builtin_Impl_Stats_##name(args_length, args_object, isolate);   \
-    }                                                                        \
-    BuiltinArguments args(args_length, args_object);                         \
-    return Builtin_Impl_##name(args, isolate);                               \
-  }                                                                          \
-                                                                             \
-  MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,  \
+#define BUILTIN(name)                                                         \
+  MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,   \
+                                                     Isolate* isolate);       \
+                                                                              \
+  V8_NOINLINE static Object* Builtin_Impl_Stats_##name(                       \
+      int args_length, Object** args_object, Isolate* isolate) {              \
+    BuiltinArguments args(args_length, args_object);                          \
+    RuntimeCallTimerScope timer(isolate, &RuntimeCallStats::Builtin_##name);  \
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.runtime"),                     \
+                 "V8.Builtin_" #name);                                        \
+    return Builtin_Impl_##name(args, isolate);                                \
+  }                                                                           \
+                                                                              \
+  MUST_USE_RESULT Object* Builtin_##name(                                     \
+      int args_length, Object** args_object, Isolate* isolate) {              \
+    DCHECK(isolate->context() == nullptr || isolate->context()->IsContext()); \
+    if (V8_UNLIKELY(TRACE_EVENT_RUNTIME_CALL_STATS_TRACING_ENABLED() ||       \
+                    FLAG_runtime_call_stats)) {                               \
+      return Builtin_Impl_Stats_##name(args_length, args_object, isolate);    \
+    }                                                                         \
+    BuiltinArguments args(args_length, args_object);                          \
+    return Builtin_Impl_##name(args, isolate);                                \
+  }                                                                           \
+                                                                              \
+  MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,   \
                                                      Isolate* isolate)
 
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