cc: Remove disabled LatencyQuery logic in OutputSurface

cc/output/output_surface.cc

Index: cc/output/output_surface.cc
diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index 46096d2e3094febd271e31a47c8668fbc1158ea2..369a152ea9d2371cb90f4c42562d6305775ad40b 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -21,7 +21,6 @@
 #include "cc/output/managed_memory_policy.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/scheduler/delay_based_time_source.h"
-#include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "third_party/khronos/GLES2/gl2.h"
@@ -34,13 +33,6 @@ using std::set;
 using std::string;
 using std::vector;
 
-namespace {
-
-const size_t kGpuLatencyHistorySize = 60;
-const double kGpuLatencyEstimationPercentile = 100.0;
-
-}
-
 namespace cc {
 
 OutputSurface::OutputSurface(scoped_refptr<ContextProvider> context_provider)
@@ -48,8 +40,7 @@ OutputSurface::OutputSurface(scoped_refptr<ContextProvider> context_provider)
       context_provider_(context_provider),
       device_scale_factor_(-1),
       external_stencil_test_enabled_(false),
-      weak_ptr_factory_(this),
-      gpu_latency_history_(kGpuLatencyHistorySize) {
+      weak_ptr_factory_(this) {
 }
 
 OutputSurface::OutputSurface(scoped_ptr<SoftwareOutputDevice> software_device)
@@ -57,8 +48,7 @@ OutputSurface::OutputSurface(scoped_ptr<SoftwareOutputDevice> software_device)
       software_device_(software_device.Pass()),
       device_scale_factor_(-1),
       external_stencil_test_enabled_(false),
-      weak_ptr_factory_(this),
-      gpu_latency_history_(kGpuLatencyHistorySize) {
+      weak_ptr_factory_(this) {
 }
 
 OutputSurface::OutputSurface(scoped_refptr<ContextProvider> context_provider,
@@ -68,8 +58,7 @@ OutputSurface::OutputSurface(scoped_refptr<ContextProvider> context_provider,
       software_device_(software_device.Pass()),
       device_scale_factor_(-1),
       external_stencil_test_enabled_(false),
-      weak_ptr_factory_(this),
-      gpu_latency_history_(kGpuLatencyHistorySize) {
+      weak_ptr_factory_(this) {
 }
 
 void OutputSurface::CommitVSyncParameters(base::TimeTicks timebase,
@@ -95,8 +84,6 @@ void OutputSurface::ReclaimResources(const CompositorFrameAck* ack) {
 
 void OutputSurface::DidLoseOutputSurface() {
   TRACE_EVENT0("cc", "OutputSurface::DidLoseOutputSurface");
-  pending_gpu_latency_query_ids_.clear();
-  available_gpu_latency_query_ids_.clear();
   client_->DidLoseOutputSurface();
 }
 
@@ -189,16 +176,6 @@ void OutputSurface::ReleaseContextProvider() {
 
 void OutputSurface::ResetContext3d() {
   if (context_provider_.get()) {
-    while (!pending_gpu_latency_query_ids_.empty()) {
-      unsigned query_id = pending_gpu_latency_query_ids_.front();
-      pending_gpu_latency_query_ids_.pop_front();
-      context_provider_->ContextGL()->DeleteQueriesEXT(1, &query_id);
-    }
-    while (!available_gpu_latency_query_ids_.empty()) {
-      unsigned query_id = available_gpu_latency_query_ids_.front();
-      available_gpu_latency_query_ids_.pop_front();
-      context_provider_->ContextGL()->DeleteQueriesEXT(1, &query_id);
-    }
     context_provider_->SetLostContextCallback(
         ContextProvider::LostContextCallback());
     context_provider_->SetMemoryPolicyChangedCallback(
@@ -254,7 +231,6 @@ void OutputSurface::SwapBuffers(CompositorFrame* frame) {
   DCHECK(context_provider_);
   DCHECK(frame->gl_frame_data);
 
-  UpdateAndMeasureGpuLatency();
   if (frame->gl_frame_data->sub_buffer_rect ==
       gfx::Rect(frame->gl_frame_data->size)) {
     context_provider_->ContextSupport()->Swap();
@@ -266,79 +242,6 @@ void OutputSurface::SwapBuffers(CompositorFrame* frame) {
   client_->DidSwapBuffers();
 }
 
-base::TimeDelta OutputSurface::GpuLatencyEstimate() {
-  if (context_provider_ && !capabilities_.adjust_deadline_for_parent)
-    return gpu_latency_history_.Percentile(kGpuLatencyEstimationPercentile);
-  else
-    return base::TimeDelta();
-}
-
-void OutputSurface::UpdateAndMeasureGpuLatency() {
-  // http://crbug.com/306690  tracks re-enabling latency queries.
-#if 0
-  // We only care about GPU latency for surfaces that do not have a parent
-  // compositor, since surfaces that do have a parent compositor can use
-  // mailboxes or delegated rendering to send frames to their parent without
-  // incurring GPU latency.
-  if (capabilities_.adjust_deadline_for_parent)
-    return;
-
-  while (pending_gpu_latency_query_ids_.size()) {
-    unsigned query_id = pending_gpu_latency_query_ids_.front();
-    unsigned query_complete = 1;
-    context_provider_->ContextGL()->GetQueryObjectuivEXT(
-        query_id, GL_QUERY_RESULT_AVAILABLE_EXT, &query_complete);
-    if (!query_complete)
-      break;
-
-    unsigned value = 0;
-    context_provider_->ContextGL()->GetQueryObjectuivEXT(
-        query_id, GL_QUERY_RESULT_EXT, &value);
-    pending_gpu_latency_query_ids_.pop_front();
-    available_gpu_latency_query_ids_.push_back(query_id);
-
-    base::TimeDelta latency = base::TimeDelta::FromMicroseconds(value);
-    base::TimeDelta latency_estimate = GpuLatencyEstimate();
-    gpu_latency_history_.InsertSample(latency);
-
-    base::TimeDelta latency_overestimate;
-    base::TimeDelta latency_underestimate;
-    if (latency > latency_estimate)
-      latency_underestimate = latency - latency_estimate;
-    else
-      latency_overestimate = latency_estimate - latency;
-    UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.GpuLatency",
-                               latency,
-                               base::TimeDelta::FromMilliseconds(1),
-                               base::TimeDelta::FromMilliseconds(100),
-                               50);
-    UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.GpuLatencyUnderestimate",
-                               latency_underestimate,
-                               base::TimeDelta::FromMilliseconds(1),
-                               base::TimeDelta::FromMilliseconds(100),
-                               50);
-    UMA_HISTOGRAM_CUSTOM_TIMES("Renderer.GpuLatencyOverestimate",
-                               latency_overestimate,
-                               base::TimeDelta::FromMilliseconds(1),
-                               base::TimeDelta::FromMilliseconds(100),
-                               50);
-  }
-
-  unsigned gpu_latency_query_id;
-  if (available_gpu_latency_query_ids_.size()) {
-    gpu_latency_query_id = available_gpu_latency_query_ids_.front();
-    available_gpu_latency_query_ids_.pop_front();
-  } else {
-    context_provider_->ContextGL()->GenQueriesEXT(1, &gpu_latency_query_id);
-  }
-
-  context_provider_->ContextGL()->BeginQueryEXT(GL_LATENCY_QUERY_CHROMIUM,
-                                                gpu_latency_query_id);
-  context_provider_->ContextGL()->EndQueryEXT(GL_LATENCY_QUERY_CHROMIUM);
-  pending_gpu_latency_query_ids_.push_back(gpu_latency_query_id);
-#endif
-}
-
 void OutputSurface::PostSwapBuffersComplete() {
   base::MessageLoop::current()->PostTask(
       FROM_HERE,