Add synthetic delay points for latency testing

gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc

Index: gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc
diff --git a/gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc b/gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc
index 7e0d515e49c172b1ede3739bdceeca60b1947758..620127b9a0526b2266fe53897beaa9fc4c848539 100644
--- a/gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc
+++ b/gpu/command_buffer/service/async_pixel_transfer_manager_egl.cc
@@ -9,6 +9,7 @@
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_synthetic_delay.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
@@ -237,7 +238,9 @@ class TransferStateInternal
     transfer_completion_.Reset();
   }
 
-  void MarkAsCompleted() {
+  void MarkAsCompleted(base::AtomicRefCount* pending_uploads) {
+    if (!base::AtomicRefCountDec(pending_uploads))
+      TRACE_EVENT_SYNTHETIC_DELAY_APPLY("gpu.AsyncTexImage");
     transfer_completion_.Signal();
   }
 
@@ -252,17 +255,19 @@ class TransferStateInternal
       AsyncTexImage2DParams tex_params,
       AsyncMemoryParams mem_params,
       ScopedSafeSharedMemory* safe_shared_memory,
-      scoped_refptr<AsyncPixelTransferUploadStats> texture_upload_stats) {
+      scoped_refptr<AsyncPixelTransferUploadStats> texture_upload_stats,
+      base::AtomicRefCount* pending_uploads) {
     TRACE_EVENT2("gpu",
                  "PerformAsyncTexImage",
                  "width",
                  tex_params.width,
                  "height",
                  tex_params.height);
+    TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE("gpu.AsyncTexImage");
     DCHECK(!thread_texture_id_);
     DCHECK_EQ(0, tex_params.level);
     if (EGL_NO_IMAGE_KHR != egl_image_) {
-      MarkAsCompleted();
+      MarkAsCompleted(pending_uploads);
       return;
     }
 
@@ -302,7 +307,7 @@ class TransferStateInternal
     }
 
     WaitForLastUpload();
-    MarkAsCompleted();
+    MarkAsCompleted(pending_uploads);
 
     DCHECK(CHECK_GL());
     if (texture_upload_stats.get()) {
@@ -315,13 +320,15 @@ class TransferStateInternal
       AsyncTexSubImage2DParams tex_params,
       AsyncMemoryParams mem_params,
       ScopedSafeSharedMemory* safe_shared_memory,
-      scoped_refptr<AsyncPixelTransferUploadStats> texture_upload_stats) {
+      scoped_refptr<AsyncPixelTransferUploadStats> texture_upload_stats,
+      base::AtomicRefCount* pending_uploads ) {
     TRACE_EVENT2("gpu",
                  "PerformAsyncTexSubImage2D",
                  "width",
                  tex_params.width,
                  "height",
                  tex_params.height);
+    TRACE_EVENT_SYNTHETIC_DELAY_ACTIVATE("gpu.AsyncTexImage");
 
     DCHECK_NE(EGL_NO_IMAGE_KHR, egl_image_);
     DCHECK_EQ(0, tex_params.level);
@@ -348,7 +355,7 @@ class TransferStateInternal
       DoTexSubImage2D(tex_params, data);
     }
     WaitForLastUpload();
-    MarkAsCompleted();
+    MarkAsCompleted(pending_uploads);
 
     DCHECK(CHECK_GL());
     if (texture_upload_stats.get()) {
@@ -520,6 +527,7 @@ void AsyncPixelTransferDelegateEGL::AsyncTexImage2D(
   state_->bind_callback_ = bind_callback;
 
   // Mark the transfer in progress.
+  base::AtomicRefCountInc(&shared_state_->pending_uploads);
   state_->MarkAsTransferIsInProgress();
 
   // Duplicate the shared memory so there is no way we can get
@@ -533,7 +541,8 @@ void AsyncPixelTransferDelegateEGL::AsyncTexImage2D(
           base::Owned(new ScopedSafeSharedMemory(safe_shared_memory_pool(),
                                                  mem_params.shared_memory,
                                                  mem_params.shm_size)),
-          shared_state_->texture_upload_stats));
+          shared_state_->texture_upload_stats,
+          &shared_state_->pending_uploads));
 
   DCHECK(CHECK_GL());
 }
@@ -554,6 +563,7 @@ void AsyncPixelTransferDelegateEGL::AsyncTexSubImage2D(
   DCHECK_EQ(tex_params.level, 0);
 
   // Mark the transfer in progress.
+  base::AtomicRefCountInc(&shared_state_->pending_uploads);
   state_->MarkAsTransferIsInProgress();
 
   // If this wasn't async allocated, we don't have an EGLImage yet.
@@ -571,7 +581,8 @@ void AsyncPixelTransferDelegateEGL::AsyncTexSubImage2D(
           base::Owned(new ScopedSafeSharedMemory(safe_shared_memory_pool(),
                                                  mem_params.shared_memory,
                                                  mem_params.shm_size)),
-          shared_state_->texture_upload_stats));
+          shared_state_->texture_upload_stats,
+          &shared_state_->pending_uploads));
 
   DCHECK(CHECK_GL());
 }
@@ -690,7 +701,8 @@ bool AsyncPixelTransferDelegateEGL::WorkAroundAsyncTexSubImage2D(
 
 AsyncPixelTransferManagerEGL::SharedState::SharedState()
     // TODO(reveman): Skip this if --enable-gpu-benchmarking is not present.
-    : texture_upload_stats(new AsyncPixelTransferUploadStats) {
+    : texture_upload_stats(new AsyncPixelTransferUploadStats),
+      pending_uploads(0) {
   std::string vendor;
   vendor = reinterpret_cast<const char*>(glGetString(GL_VENDOR));
   is_imagination = vendor.find("Imagination") != std::string::npos;