Revert of Adding task runner/ message loop to tests that use IsolateHolder. (patchset #4 id:60001 of https://codereview.chromium.org/1130433002/)

Reason for revert:
speculative revert, gin unittests doesn't compile on mac builders anymore

Original issue's description:
> Adding task runner/ message loop to tests that use IsolateHolder.
>
> For adding v8 heap memory dump provider, the gin::IsolateHolder needs
> to have a task runner at initialization. The tests which don't
> initiallize task runner when initialization are changed in this CL to
> have either the message loop initializaed earlier or a dummy task
> runner. Refer crrev.com/1088683003 for the dump provider.
>
> BUG=476013
>
> Committed: https://crrev.com/54d19441b064ae06604c6a26c3863a091a8bb8bb
> Cr-Commit-Position: refs/heads/master@{#328531}

TBR=primiano@chromium.org,skyostil@chromium.org,ssid@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=476013

Review URL: https://codereview.chromium.org/1129863002

Cr-Commit-Position: refs/heads/master@{#328538}

4 files changed, 13 insertions, 15 deletions

diff --git a/gin/modules/module_registry_unittest.cc b/gin/modules/module_registry_unittest.cc
index 00c6a94..2d6e6daf 100644
--- a/gin/modules/module_registry_unittest.cc
+++ b/gin/modules/module_registry_unittest.cc
@@ -5,6 +5,7 @@
 #include "gin/modules/module_registry.h"
 
 #include "base/bind.h"
+#include "base/message_loop/message_loop.h"
 #include "gin/modules/module_registry_observer.h"
 #include "gin/modules/module_runner_delegate.h"
 #include "gin/public/context_holder.h"
@@ -24,6 +25,7 @@ struct TestHelper {
         scope(runner.get()) {
   }
 
+  base::MessageLoop message_loop;
   ModuleRunnerDelegate delegate;
   scoped_ptr<ShellRunner> runner;
   Runner::Scope scope;
diff --git a/gin/modules/timer_unittest.cc b/gin/modules/timer_unittest.cc
index 612275e..705bdc5 100644
--- a/gin/modules/timer_unittest.cc
+++ b/gin/modules/timer_unittest.cc
@@ -64,10 +64,9 @@ struct TestHelper {
                           result->GetWrapper(isolate));
   }
 
-  void QuitSoon(base::MessageLoop* message_loop) {
-    message_loop->PostDelayedTask(FROM_HERE,
-                                  base::MessageLoop::QuitWhenIdleClosure(),
-                                  base::TimeDelta::FromMilliseconds(0));
+  void QuitSoon() {
+    loop.PostDelayedTask(FROM_HERE, base::MessageLoop::QuitWhenIdleClosure(),
+                         base::TimeDelta::FromMilliseconds(0));
   }
 
   ShellRunnerDelegate delegate;
@@ -75,6 +74,7 @@ struct TestHelper {
   Runner::Scope scope;
   Handle<TimerModule> timer_module;
   Handle<Result> result;
+  base::MessageLoop loop;
 };
 
 }  // namespace
@@ -91,8 +91,8 @@ TEST_F(TimerUnittest, OneShot) {
   helper.runner->Run(source, "script");
   EXPECT_EQ(0, helper.result->count());
 
-  helper.QuitSoon(&message_loop_);
-  message_loop_.Run();
+  helper.QuitSoon();
+  helper.loop.Run();
   EXPECT_EQ(1, helper.result->count());
 }
 
@@ -107,8 +107,8 @@ TEST_F(TimerUnittest, OneShotCancel) {
   helper.runner->Run(source, "script");
   EXPECT_EQ(0, helper.result->count());
 
-  helper.QuitSoon(&message_loop_);
-  message_loop_.Run();
+  helper.QuitSoon();
+  helper.loop.Run();
   EXPECT_EQ(0, helper.result->count());
 }
 
@@ -128,7 +128,7 @@ TEST_F(TimerUnittest, Repeating) {
   helper.runner->Run(source, "script");
   EXPECT_EQ(0, helper.result->count());
 
-  message_loop_.Run();
+  helper.loop.Run();
   EXPECT_EQ(3, helper.result->count());
 }
 
@@ -143,9 +143,9 @@ TEST_F(TimerUnittest, TimerCallbackToDestroyedRunner) {
   EXPECT_EQ(0, helper.result->count());
 
   // Destroy runner, which should destroy the timer object we created.
-  helper.QuitSoon(&message_loop_);
+  helper.QuitSoon();
   helper.runner.reset(NULL);
-  message_loop_.Run();
+  helper.loop.Run();
 
   // Timer should not have run because it was deleted.
   EXPECT_EQ(0, helper.result->count());
diff --git a/gin/shell_runner_unittest.cc b/gin/shell_runner_unittest.cc
index 4e4b9c2f..340b673 100644
--- a/gin/shell_runner_unittest.cc
+++ b/gin/shell_runner_unittest.cc
@@ -5,7 +5,6 @@
 #include "gin/shell_runner.h"
 
 #include "base/compiler_specific.h"
-#include "base/message_loop/message_loop.h"
 #include "gin/array_buffer.h"
 #include "gin/converter.h"
 #include "gin/public/isolate_holder.h"
@@ -24,7 +23,6 @@ using v8::String;
 namespace gin {
 
 TEST(RunnerTest, Run) {
-  base::MessageLoop message_loop;
   std::string source = "this.result = 'PASS';\n";
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
diff --git a/gin/test/v8_test.h b/gin/test/v8_test.h
index 592b889..e9209ce 100644
--- a/gin/test/v8_test.h
+++ b/gin/test/v8_test.h
@@ -8,7 +8,6 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "v8/include/v8.h"
 
@@ -27,7 +26,6 @@ class V8Test : public testing::Test {
   void TearDown() override;
 
  protected:
-  base::MessageLoop message_loop_;
   scoped_ptr<IsolateHolder> instance_;
   v8::Persistent<v8::Context> context_;