v8: Prep for removing TRACE_EVENT_SCOPED_CONTEXT.

It's only used in tests, and for some reason v8 refers to a macro defined
in src.git, so I need to remove this in v8 first before I can remove it
in Chromium.

Bug: chromium:934255
Change-Id: I31ea32aa43cf7a5f518def7b91dce99dcb268709
Reviewed-on: https://chromium-review.googlesource.com/c/1480911Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59769}

src/tracing/trace-event.h

@@ -270,27 +270,6 @@ enum CategoryGroupEnabledFlags {
   INTERNAL_TRACE_EVENT_ADD_WITH_ID_AND_TIMESTAMP(                      \
       phase, category_group, name, id, timestamp, flags, ##__VA_ARGS__)
 
-// Enter and leave a context based on the current scope.
-#define INTERNAL_TRACE_EVENT_SCOPED_CONTEXT(category_group, name, context) \
-  struct INTERNAL_TRACE_EVENT_UID(ScopedContext) {                         \
-   public:                                                                 \
-    INTERNAL_TRACE_EVENT_UID(ScopedContext)(uint64_t cid) : cid_(cid) {    \
-      TRACE_EVENT_ENTER_CONTEXT(category_group, name, cid_);               \
-    }                                                                      \
-    ~INTERNAL_TRACE_EVENT_UID(ScopedContext)() {                           \
-      TRACE_EVENT_LEAVE_CONTEXT(category_group, name, cid_);               \
-    }                                                                      \
-                                                                           \
-   private:                                                                \
-    /* Local class friendly DISALLOW_COPY_AND_ASSIGN */                    \
-    INTERNAL_TRACE_EVENT_UID(ScopedContext)                                \
-    (const INTERNAL_TRACE_EVENT_UID(ScopedContext)&) {}                    \
-    void operator=(const INTERNAL_TRACE_EVENT_UID(ScopedContext)&) {}      \
-    uint64_t cid_;                                                         \
-  };                                                                       \
-  INTERNAL_TRACE_EVENT_UID(ScopedContext)                                  \
-  INTERNAL_TRACE_EVENT_UID(scoped_context)(context);
-
 #define TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name) \
   INTERNAL_TRACE_EVENT_CALL_STATS_SCOPED(isolate, category_group, name)
 

test/cctest/test-trace-event.cc

@@ -234,26 +234,6 @@ TEST(TestEventWithId) {
   CHECK_EQ(event_id, GET_TRACE_OBJECT(1)->id);
 }
 
-TEST(TestEventInContext) {
-  MockTracingPlatform platform;
-
-  static uint64_t isolate_id = 0x20151021;
-  {
-    TRACE_EVENT_SCOPED_CONTEXT("v8-cat", "Isolate", isolate_id);
-    TRACE_EVENT0("v8-cat", "e");
-  }
-
-  CHECK_EQ(3, GET_TRACE_OBJECTS_LIST->size());
-  CHECK_EQ(TRACE_EVENT_PHASE_ENTER_CONTEXT, GET_TRACE_OBJECT(0)->phase);
-  CHECK_EQ("Isolate", GET_TRACE_OBJECT(0)->name);
-  CHECK_EQ(isolate_id, GET_TRACE_OBJECT(0)->id);
-  CHECK_EQ(TRACE_EVENT_PHASE_COMPLETE, GET_TRACE_OBJECT(1)->phase);
-  CHECK_EQ("e", GET_TRACE_OBJECT(1)->name);
-  CHECK_EQ(TRACE_EVENT_PHASE_LEAVE_CONTEXT, GET_TRACE_OBJECT(2)->phase);
-  CHECK_EQ("Isolate", GET_TRACE_OBJECT(2)->name);
-  CHECK_EQ(isolate_id, GET_TRACE_OBJECT(2)->id);
-}
-
 TEST(TestEventWithTimestamp) {
   MockTracingPlatform platform;