Added support for TimeStamp queries using QueryCounterEXT.

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index d4e77f2d2c492dc9f1951b740ba3c451d8dcb50a..37a1e9c80412d13cb8bb3fa9d8900809224cbd58 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -4888,7 +4888,6 @@ void GLES2Implementation::BeginQueryEXT(GLenum target, GLuint id) {
         return;
       }
       break;
-    // TODO(dyen): Also support GL_TIMESTAMP.
     case GL_TIME_ELAPSED_EXT:
       if (!capabilities_.timer_queries) {
         SetGLError(
@@ -4899,7 +4898,7 @@ void GLES2Implementation::BeginQueryEXT(GLenum target, GLuint id) {
       break;
     default:
       SetGLError(
-          GL_INVALID_OPERATION, "glBeginQueryEXT", "unknown query target");
+          GL_INVALID_ENUM, "glBeginQueryEXT", "unknown query target");
       return;
   }
 
@@ -4939,6 +4938,44 @@ void GLES2Implementation::EndQueryEXT(GLenum target) {
     CheckGLError();
 }
 
+void GLES2Implementation::QueryCounterEXT(GLuint id, GLenum target) {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] QueryCounterEXT("
+                 << id
+                 << ", " << GLES2Util::GetStringQueryTarget(target) << ")");
+
+  // Check capabilities

[piman, 2015/07/16 01:05:52]

nit: remove superfluous comment

[David Yen, 2015/07/16 20:21:12]

Done.

+  switch (target) {
+    case GL_TIMESTAMP_EXT:
+      if (!capabilities_.timer_queries) {
+        SetGLError(
+            GL_INVALID_OPERATION, "glQueryCounterEXT",
+            "not enabled for timing queries");
+        return;
+      }
+      break;
+    default:
+      SetGLError(
+          GL_INVALID_ENUM, "glQueryCounterEXT", "unknown query target");
+      return;
+  }
+
+  // id = 0 INV_OP

[piman, 2015/07/16 01:05:52]

nit: remove superfluous comment

[David Yen, 2015/07/16 20:21:12]

Done.

+  if (id == 0) {
+    SetGLError(GL_INVALID_OPERATION, "glQueryCounterEXT", "id is 0");
+    return;
+  }
+
+  // if not GENned INV_OPERATION

[piman, 2015/07/16 01:05:52]

nit: remove superfluous comment

[David Yen, 2015/07/16 20:21:12]

Done.

+  if (!query_id_allocator_->InUse(id)) {
+    SetGLError(GL_INVALID_OPERATION, "glQueryCounterEXT", "invalid id");
+    return;
+  }
+
+  if (query_tracker_->QueryCounter(id, target, this))
+    CheckGLError();
+}
+
 void GLES2Implementation::GetQueryivEXT(
     GLenum target, GLenum pname, GLint* params) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();