Added disjoint context class which manages disjoints within gpu timing.

gpu/perftests/texture_upload_perftest.cc

Index: gpu/perftests/texture_upload_perftest.cc
diff --git a/gpu/perftests/texture_upload_perftest.cc b/gpu/perftests/texture_upload_perftest.cc
index 2e9ef6cea4346d217eeae515b89db88f9e0cf40f..4cc7789f3e2729959150a733011bf9b4d00a4ddf 100644
--- a/gpu/perftests/texture_upload_perftest.cc
+++ b/gpu/perftests/texture_upload_perftest.cc
@@ -122,10 +122,10 @@ class TextureUploadPerfTest : public testing::Test {
 
     glViewport(0, 0, size_.width(), size_.height());
 
-    if (gpu_timing_.Initialize(gl_context_.get())) {
+    gpu_timing_.Initialize(gl_context_.get());
+    if (gpu_timing_.IsAvailable()) {
       LOG(INFO) << "Gpu timing initialized with timer type: "
                 << gpu_timing_.GetTimerTypeName();
-      gpu_timing_.CheckAndResetTimerErrors();

[Daniele Castagna, 2015/02/23 22:21:19]

This is needed to invalidate the disjoint error that is going to be checked when
crrev.com/944073005 lands.

       gpu_timing_.InvalidateTimerOffset();
     } else {
       LOG(WARNING) << "Can't initialize gpu timing";