[Extensions] Hopefully de-flake MessagingUtilTest.TestMaximumMessageSize

MessagingUtilTest.TestMaximumMessageSize exercises our extension message
limits by trying to send large messages. Unfortunately, large messages
take a long time to construct, which, it appears, can result in the test
timing out.

The test currently runs two virtually-identical cases (a massive string
and a massive JSON-ified string). Remove the JSON-ified case to cut the
effective test duration in half.

Bug: 1093817
Change-Id: I597b8ad1c66fb894c8b1520230c779aa70107c6f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2259473Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781379}

extensions/renderer/messaging_util_unittest.cc

@@ -28,26 +28,13 @@ TEST_F(MessagingUtilTest, TestMaximumMessageSize) {
   constexpr char kMessageTooLongError[] =
       "Message length exceeded maximum allowed length.";
 
-  {
-    v8::Local<v8::Value> long_message =
-        V8ValueFromScriptSource(context, "'a'.repeat(1024 *1024 * 65)");
-    std::string error;
-    std::unique_ptr<Message> message =
-        messaging_util::MessageFromV8(context, long_message, &error);
-    EXPECT_FALSE(message);
-    EXPECT_EQ(kMessageTooLongError, error);
-  }
-
-  {
-    v8::Local<v8::Value> long_json_message = V8ValueFromScriptSource(
-        context, "(JSON.stringify('a'.repeat(1024 *1024 * 65)))");
-    ASSERT_TRUE(long_json_message->IsString());
-    std::string error;
-    std::unique_ptr<Message> message = messaging_util::MessageFromV8(
-        context, long_json_message.As<v8::String>(), &error);
-    EXPECT_FALSE(message);
-    EXPECT_EQ(kMessageTooLongError, error);
-  }
+  v8::Local<v8::Value> long_message =
+      V8ValueFromScriptSource(context, "'a'.repeat(1024 *1024 * 65)");
+  std::string error;
+  std::unique_ptr<Message> message =
+      messaging_util::MessageFromV8(context, long_message, &error);
+  EXPECT_FALSE(message);
+  EXPECT_EQ(kMessageTooLongError, error);
 }
 
 TEST_F(MessagingUtilTest, TestParseMessageOptionsFrameId) {