Debug: Add angle_enable_trace_events

Include the following GN arg to print all GLES and EGL commands:

    angle_enable_trace_events = true

Bug: angleproject:7126
Change-Id: I78eb061c10ed519d6a0b0357eea11567d1cfb518
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3551656
Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Cody Northrop <cnorthrop@google.com>

BUILD.gn

@@ -131,6 +131,11 @@ config("internal_config") {
     defines += [ "ANGLE_ENABLE_TRACE_ANDROID_LOGCAT=1" ]
   }
 
+  # When used with angle_enable_trace, enables logging every GLES/EGL API command to the terminal
+  if (angle_enable_trace_events) {
+    defines += [ "ANGLE_ENABLE_TRACE_EVENTS=1" ]
+  }
+
   if (is_chromeos) {
     defines += [ "ANGLE_PLATFORM_CHROMEOS" ]
   }

doc/DebuggingTips.md

@@ -46,6 +46,11 @@ additional levels of "trace" messages will be logged when the following GN arg i
 angle_enable_trace = true
 ```
 
+To log all GLES and EGL commands submitted by an application, including the following flag:
+```
+angle_enable_trace_events = true
+```
+
 ## Debug Angle on Android
 
 Android is built as an Android APK, which makes it more difficult to debug an APK that is using ANGLE.  The following information can allow you to debug ANGLE with LLDB.

gni/angle.gni

@@ -187,6 +187,7 @@ declare_args() {
   angle_enable_glsl = angle_enable_gl || use_ozone
   angle_enable_trace = false
   angle_enable_trace_android_logcat = false
+  angle_enable_trace_events = false
 
   # Disable the layers in ubsan builds because of really slow builds.
   # Vulkan Validation Layers require Android NDK API level 26, i.e. Oreo, due to

src/common/debug.cpp

@@ -232,7 +232,7 @@ void Trace(LogSeverity severity, const char *message)
     }
 
     if (severity == LOG_FATAL || severity == LOG_ERR || severity == LOG_WARN ||
-#if defined(ANGLE_ENABLE_TRACE_ANDROID_LOGCAT)
+#if defined(ANGLE_ENABLE_TRACE_ANDROID_LOGCAT) || defined(ANGLE_ENABLE_TRACE_EVENTS)
         severity == LOG_EVENT ||
 #endif
         severity == LOG_INFO)