Add GL_CHROMIUM_get_error_query

Makes it possible to asynchronously query GL errors.

TEST=unit tests
BUG=133630


Review URL: https://chromiumcodereview.appspot.com/10577037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@145739 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 324 insertions, 60 deletions

diff --git a/gpu/command_buffer/client/atomicops.h b/gpu/command_buffer/client/atomicops.h
index 7fa68bd..517ef07 100644
--- a/gpu/command_buffer/client/atomicops.h
+++ b/gpu/command_buffer/client/atomicops.h
@@ -11,7 +11,7 @@
 
 namespace gpu {
 
-void MemoryBarrier();
+GPU_EXPORT void MemoryBarrier();
 
 class LockImpl;
 class GPU_EXPORT Lock {
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index ca3a9e7..d6f7723 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -503,6 +503,10 @@ GLES2Implementation::~GLES2Implementation() {
   Finish();
 }
 
+GLES2CmdHelper* GLES2Implementation::helper() const {
+  return helper_;
+}
+
 GLuint GLES2Implementation::MakeTextureId() {
   GLuint id;
   GetIdHandler(id_namespaces::kTextures)->MakeIds(this, 0, 1, &id);
@@ -592,11 +596,28 @@ GLenum GLES2Implementation::GetError() {
   return err;
 }
 
+GLenum GLES2Implementation::GetClientSideGLError() {
+  if (error_bits_ == 0) {
+    return GL_NO_ERROR;
+  }
+
+  GLenum error = GL_NO_ERROR;
+  for (uint32 mask = 1; mask != 0; mask = mask << 1) {
+    if ((error_bits_ & mask) != 0) {
+      error = GLES2Util::GLErrorBitToGLError(mask);
+      break;
+    }
+  }
+  error_bits_ &= ~GLES2Util::GLErrorToErrorBit(error);
+  return error;
+}
+
 GLenum GLES2Implementation::GetGLError() {
   TRACE_EVENT0("gpu", "GLES2::GetGLError");
   // Check the GL error first, then our wrapped error.
   typedef gles2::GetError::Result Result;
   Result* result = GetResultAs<Result*>();
+  // If we couldn't allocate a result the context is lost.
   if (!result) {
     return GL_NO_ERROR;
   }
@@ -604,16 +625,9 @@ GLenum GLES2Implementation::GetGLError() {
   helper_->GetError(GetResultShmId(), GetResultShmOffset());
   WaitForCmd();
   GLenum error = *result;
-  if (error == GL_NO_ERROR && error_bits_ != 0) {
-    for (uint32 mask = 1; mask != 0; mask = mask << 1) {
-      if ((error_bits_ & mask) != 0) {
-        error = GLES2Util::GLErrorBitToGLError(mask);
-        break;
-      }
-    }
-  }
-
-  if (error != GL_NO_ERROR) {
+  if (error == GL_NO_ERROR) {
+    error = GetClientSideGLError();
+  } else {
     // There was an error, clear the corresponding wrapped error.
     error_bits_ &= ~GLES2Util::GLErrorToErrorBit(error);
   }
@@ -3085,11 +3099,7 @@ void GLES2Implementation::BeginQueryEXT(GLenum target, GLuint id) {
 
   current_query_ = query;
 
-  // init memory, inc count
-  query->MarkAsActive();
-
-  // tell service about id, shared memory and count
-  helper_->BeginQueryEXT(target, id, query->shm_id(), query->shm_offset());
+  query->Begin(this);
 }
 
 void GLES2Implementation::EndQueryEXT(GLenum target) {
@@ -3108,8 +3118,7 @@ void GLES2Implementation::EndQueryEXT(GLenum target) {
     return;
   }
 
-  helper_->EndQueryEXT(target, current_query_->submit_count());
-  current_query_->MarkAsPending(helper_->InsertToken());
+  current_query_->End(this);
   current_query_ = NULL;
 }
 
diff --git a/gpu/command_buffer/client/gles2_implementation.h b/gpu/command_buffer/client/gles2_implementation.h
index bf68273..9b07a32 100644
--- a/gpu/command_buffer/client/gles2_implementation.h
+++ b/gpu/command_buffer/client/gles2_implementation.h
@@ -198,9 +198,10 @@ class GLES2_IMPL_EXPORT GLES2Implementation {
 
   // The GLES2CmdHelper being used by this GLES2Implementation. You can use
   // this to issue cmds at a lower level for certain kinds of optimization.
-  GLES2CmdHelper* helper() const {
-    return helper_;
-  }
+  GLES2CmdHelper* helper() const;
+
+  // Gets client side generated errors.
+  GLenum GetClientSideGLError();
 
   // Include the auto-generated part of this class. We split this because
   // it means we can easily edit the non-auto generated parts right here in
diff --git a/gpu/command_buffer/client/gles2_implementation_unittest.cc b/gpu/command_buffer/client/gles2_implementation_unittest.cc
index b7f599b4..c64696f 100644
--- a/gpu/command_buffer/client/gles2_implementation_unittest.cc
+++ b/gpu/command_buffer/client/gles2_implementation_unittest.cc
@@ -2564,6 +2564,60 @@ TEST_F(GLES2ImplementationTest, BeginEndQueryEXT) {
   EXPECT_EQ(0u, available);
 }
 
+TEST_F(GLES2ImplementationTest, ErrorQuery) {
+  GLuint id = 0;
+  gl_->GenQueriesEXT(1, &id);
+  ClearCommands();
+
+  // Test BeginQueryEXT does NOT insert commands.
+  gl_->BeginQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM, id);
+  EXPECT_TRUE(NoCommandsWritten());
+  QueryTracker::Query* query = GetQuery(id);
+  ASSERT_TRUE(query != NULL);
+
+  // Test EndQueryEXT sends both begin and end command
+  struct EndCmds {
+    BeginQueryEXT begin_query;
+    EndQueryEXT end_query;
+  };
+  EndCmds expected_end_cmds;
+  expected_end_cmds.begin_query.Init(
+      GL_GET_ERROR_QUERY_CHROMIUM, id, query->shm_id(), query->shm_offset());
+  expected_end_cmds.end_query.Init(
+      GL_GET_ERROR_QUERY_CHROMIUM, query->submit_count());
+  const void* commands = GetPut();
+  gl_->EndQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM);
+  EXPECT_EQ(0, memcmp(
+      &expected_end_cmds, commands, sizeof(expected_end_cmds)));
+  ClearCommands();
+
+  // Check result is not yet available.
+  GLuint available = 0xBDu;
+  gl_->GetQueryObjectuivEXT(id, GL_QUERY_RESULT_AVAILABLE_EXT, &available);
+  EXPECT_TRUE(NoCommandsWritten());
+  EXPECT_EQ(0u, available);
+
+  // Test no commands are sent if there is a client side error.
+
+  // Generate a client side error
+  gl_->ActiveTexture(GL_TEXTURE0 - 1);
+
+  gl_->BeginQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM, id);
+  gl_->EndQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM);
+  EXPECT_TRUE(NoCommandsWritten());
+
+  // Check result is available.
+  gl_->GetQueryObjectuivEXT(id, GL_QUERY_RESULT_AVAILABLE_EXT, &available);
+  EXPECT_TRUE(NoCommandsWritten());
+  EXPECT_NE(0u, available);
+
+  // Check result.
+  GLuint result = 0xBDu;
+  gl_->GetQueryObjectuivEXT(id, GL_QUERY_RESULT_EXT, &result);
+  EXPECT_TRUE(NoCommandsWritten());
+  EXPECT_EQ(static_cast<GLuint>(GL_INVALID_ENUM), result);
+}
+
 #include "gpu/command_buffer/client/gles2_implementation_unittest_autogen.h"
 
 }  // namespace gles2
diff --git a/gpu/command_buffer/client/query_tracker.cc b/gpu/command_buffer/client/query_tracker.cc
index 5d08f2e..e1e150f 100644
--- a/gpu/command_buffer/client/query_tracker.cc
+++ b/gpu/command_buffer/client/query_tracker.cc
@@ -2,10 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
 #include "../client/query_tracker.h"
 
 #include "../client/atomicops.h"
-#include "../client/cmd_buffer_helper.h"
+#include "../client/gles2_cmd_helper.h"
+#include "../client/gles2_implementation.h"
 #include "../client/mapped_memory.h"
 
 namespace gpu {
@@ -51,6 +55,44 @@ void QuerySyncManager::Free(const QuerySyncManager::QueryInfo& info) {
   free_queries_.push(info);
 }
 
+void QueryTracker::Query::Begin(GLES2Implementation* gl) {
+  // init memory, inc count
+  MarkAsActive();
+
+  switch (target()) {
+    case GL_GET_ERROR_QUERY_CHROMIUM:
+      // To nothing on begin for error queries.
+      break;
+    default:
+      // tell service about id, shared memory and count
+      gl->helper()->BeginQueryEXT(target(), id(), shm_id(), shm_offset());
+      break;
+  }
+}
+
+void QueryTracker::Query::End(GLES2Implementation* gl) {
+  switch (target()) {
+    case GL_GET_ERROR_QUERY_CHROMIUM: {
+      GLenum error = gl->GetClientSideGLError();
+      if (error == GL_NO_ERROR) {
+        // There was no error so start the query on the serivce.
+        // it will end immediately.
+        gl->helper()->BeginQueryEXT(target(), id(), shm_id(), shm_offset());
+      } else {
+        // There's an error on the client, no need to bother the service. just
+        // set the query as completed and return the error.
+        if (error != GL_NO_ERROR) {
+          state_ = kComplete;
+          result_ = error;
+          return;
+        }
+      }
+    }
+  }
+  gl->helper()->EndQueryEXT(target(), submit_count());
+  MarkAsPending(gl->helper()->InsertToken());
+}
+
 bool QueryTracker::Query::CheckResultsAvailable(
     CommandBufferHelper* helper) {
   if (Pending()) {
diff --git a/gpu/command_buffer/client/query_tracker.h b/gpu/command_buffer/client/query_tracker.h
index 9746497..adaba82 100644
--- a/gpu/command_buffer/client/query_tracker.h
+++ b/gpu/command_buffer/client/query_tracker.h
@@ -8,9 +8,9 @@
 #include <GLES2/gl2.h>
 
 #include <queue>
-#include "../../gpu_export.h"
 #include "../client/hash_tables.h"
 #include "../common/gles2_cmd_format.h"
+#include "gles2_impl_export.h"
 
 namespace gpu {
 
@@ -19,8 +19,10 @@ class MappedMemoryManager;
 
 namespace gles2 {
 
+class GLES2Implementation;
+
 // Manages buckets of QuerySync instances in mapped memory.
-class GPU_EXPORT QuerySyncManager {
+class GLES2_IMPL_EXPORT QuerySyncManager {
  public:
   static const size_t kSyncsPerBucket = 4096;
 
@@ -57,9 +59,9 @@ class GPU_EXPORT QuerySyncManager {
 };
 
 // Tracks queries for client side of command buffer.
-class GPU_EXPORT QueryTracker {
+class GLES2_IMPL_EXPORT QueryTracker {
  public:
-  class GPU_EXPORT Query {
+  class GLES2_IMPL_EXPORT Query {
    public:
     enum State {
       kUninitialized,  // never used
@@ -126,6 +128,9 @@ class GPU_EXPORT QueryTracker {
 
     uint32 GetResult() const;
 
+    void Begin(GLES2Implementation* gl);
+    void End(GLES2Implementation* gl);
+
    private:
     friend class QueryTracker;
     friend class QueryTrackerTest;
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index 7983ffd..c7dce24 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -176,17 +176,18 @@ void FeatureInfo::AddFeatures(const char* desired_features) {
 
   bool npot_ok = false;
 
+  AddExtensionString("GL_ANGLE_translated_shader_source");
   AddExtensionString("GL_CHROMIUM_bind_uniform_location");
-  AddExtensionString("GL_CHROMIUM_resource_safe");
-  AddExtensionString("GL_CHROMIUM_resize");
-  AddExtensionString("GL_CHROMIUM_strict_attribs");
-  AddExtensionString("GL_CHROMIUM_rate_limit_offscreen_context");
-  AddExtensionString("GL_CHROMIUM_set_visibility");
-  AddExtensionString("GL_CHROMIUM_discard_framebuffer");
   AddExtensionString("GL_CHROMIUM_command_buffer_query");
   AddExtensionString("GL_CHROMIUM_copy_texture");
+  AddExtensionString("GL_CHROMIUM_discard_framebuffer");
+  AddExtensionString("GL_CHROMIUM_get_error_query");
+  AddExtensionString("GL_CHROMIUM_rate_limit_offscreen_context");
+  AddExtensionString("GL_CHROMIUM_resize");
+  AddExtensionString("GL_CHROMIUM_resource_safe");
+  AddExtensionString("GL_CHROMIUM_set_visibility");
+  AddExtensionString("GL_CHROMIUM_strict_attribs");
   AddExtensionString("GL_CHROMIUM_texture_mailbox");
-  AddExtensionString("GL_ANGLE_translated_shader_source");
 
   if (!disallowed_features_.gpu_memory_manager)
     AddExtensionString("GL_CHROMIUM_gpu_memory_manager");
diff --git a/gpu/command_buffer/service/gl_utils.h b/gpu/command_buffer/service/gl_utils.h
index 316c3bb..5788670 100644
--- a/gpu/command_buffer/service/gl_utils.h
+++ b/gpu/command_buffer/service/gl_utils.h
@@ -86,6 +86,9 @@
 // GL_CHROMIUM_command_buffer_query
 #define GL_COMMANDS_ISSUED_CHROMIUM            0x84F2
 
+/* GL_CHROMIUM_get_error_query */
+#define GL_GET_ERROR_QUERY_CHROMIUM            0x84F3
+
 // GL_OES_texure_3D
 #define GL_SAMPLER_3D_OES                      0x8B5F
 
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 7510160..81ecee4 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -514,6 +514,8 @@ class GLES2DecoderImpl : public base::SupportsWeakPtr<GLES2DecoderImpl>,
   virtual bool GetServiceTextureId(uint32 client_texture_id,
                                    uint32* service_texture_id);
 
+  virtual uint32 GetGLError() OVERRIDE;
+
   // Restores the current state to the user's settings.
   void RestoreCurrentFramebufferBindings();
   void RestoreCurrentRenderbufferBindings();
@@ -1176,9 +1178,6 @@ class GLES2DecoderImpl : public base::SupportsWeakPtr<GLES2DecoderImpl>,
   // false if pname is unknown.
   bool GetNumValuesReturnedForGLGet(GLenum pname, GLsizei* num_values);
 
-  // Gets the GLError through our wrapper.
-  GLenum GetGLError();
-
   // Gets the GLError and stores it in our wrapper. Effectively
   // this lets us peek at the error without losing it.
   GLenum PeekGLError();
@@ -5046,7 +5045,7 @@ void GLES2DecoderImpl::DoUseProgram(GLuint program) {
   }
 }
 
-GLenum GLES2DecoderImpl::GetGLError() {
+uint32 GLES2DecoderImpl::GetGLError() {
   // Check the GL error first, then our wrapped error.
   GLenum error = glGetError();
   if (error == GL_NO_ERROR && error_bits_ != 0) {
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.h b/gpu/command_buffer/service/gles2_cmd_decoder.h
index a5d00d9..cc604fc 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.h
@@ -167,6 +167,9 @@ class GPU_EXPORT GLES2Decoder : public CommonDecoder {
       int height,
       bool is_texture_immutable) = 0;
 
+  // Gets the GL error for this context.
+  virtual uint32 GetGLError() = 0;
+
   // A callback for messages from the decoder.
   virtual void SetMsgCallback(const MsgCallback& callback) = 0;
 
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_mock.h b/gpu/command_buffer/service/gles2_cmd_decoder_mock.h
index e5bdf30..073b0c1 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_mock.h
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_mock.h
@@ -72,6 +72,7 @@ class MockGLES2Decoder : public GLES2Decoder {
       int width,
       int height,
       bool is_texture_immutable));
+  MOCK_METHOD0(GetGLError,  uint32());
   MOCK_METHOD1(SetMsgCallback, void(const MsgCallback& callback));
 
   DISALLOW_COPY_AND_ASSIGN(MockGLES2Decoder);
diff --git a/gpu/command_buffer/service/query_manager.cc b/gpu/command_buffer/service/query_manager.cc
index 14a4ab4..0f94d46 100644
--- a/gpu/command_buffer/service/query_manager.cc
+++ b/gpu/command_buffer/service/query_manager.cc
@@ -7,7 +7,7 @@
 #include "base/logging.h"
 #include "base/time.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
-#include "gpu/command_buffer/service/common_decoder.h"
+#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/command_buffer/service/feature_info.h"
 
 namespace gpu {
@@ -120,8 +120,52 @@ void CommandsIssuedQuery::Destroy(bool /* have_context */) {
 CommandsIssuedQuery::~CommandsIssuedQuery() {
 }
 
+class GetErrorQuery : public QueryManager::Query {
+ public:
+  GetErrorQuery(
+      QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset);
+
+  virtual bool Begin() OVERRIDE;
+  virtual bool End(uint32 submit_count) OVERRIDE;
+  virtual bool Process() OVERRIDE;
+  virtual void Destroy(bool have_context) OVERRIDE;
+
+ protected:
+  virtual ~GetErrorQuery();
+
+ private:
+};
+
+GetErrorQuery::GetErrorQuery(
+      QueryManager* manager, GLenum target, int32 shm_id, uint32 shm_offset)
+    : Query(manager, target, shm_id, shm_offset) {
+}
+
+bool GetErrorQuery::Begin() {
+  return true;
+}
+
+bool GetErrorQuery::End(uint32 submit_count) {
+  MarkAsPending(submit_count);
+  return MarkAsCompleted(manager()->decoder()->GetGLError());
+}
+
+bool GetErrorQuery::Process() {
+  NOTREACHED();
+  return true;
+}
+
+void GetErrorQuery::Destroy(bool /* have_context */) {
+  if (!IsDeleted()) {
+    MarkAsDeleted();
+  }
+}
+
+GetErrorQuery::~GetErrorQuery() {
+}
+
 QueryManager::QueryManager(
-    CommonDecoder* decoder,
+    GLES2Decoder* decoder,
     FeatureInfo* feature_info)
     : decoder_(decoder),
       use_arb_occlusion_query2_for_occlusion_query_boolean_(
@@ -159,6 +203,9 @@ QueryManager::Query* QueryManager::CreateQuery(
     case GL_COMMANDS_ISSUED_CHROMIUM:
       query = new CommandsIssuedQuery(this, target, shm_id, shm_offset);
       break;
+    case GL_GET_ERROR_QUERY_CHROMIUM:
+      query = new GetErrorQuery(this, target, shm_id, shm_offset);
+      break;
     default: {
       GLuint service_id = 0;
       glGenQueriesARB(1, &service_id);
@@ -253,7 +300,7 @@ QueryManager::Query::~Query() {
 bool QueryManager::Query::MarkAsCompleted(GLuint result) {
   DCHECK(pending_);
   QuerySync* sync = manager_->decoder_->GetSharedMemoryAs<QuerySync*>(
-          shm_id_, shm_offset_, sizeof(*sync));
+      shm_id_, shm_offset_, sizeof(*sync));
   if (!sync) {
     return false;
   }
diff --git a/gpu/command_buffer/service/query_manager.h b/gpu/command_buffer/service/query_manager.h
index 7e3f38d..f6d3942 100644
--- a/gpu/command_buffer/service/query_manager.h
+++ b/gpu/command_buffer/service/query_manager.h
@@ -17,7 +17,7 @@
 
 namespace gpu {
 
-class CommonDecoder;
+class GLES2Decoder;
 
 namespace gles2 {
 
@@ -132,7 +132,7 @@ class GPU_EXPORT QueryManager {
   };
 
   QueryManager(
-      CommonDecoder* decoder,
+      GLES2Decoder* decoder,
       FeatureInfo* feature_info);
   ~QueryManager();
 
@@ -162,6 +162,10 @@ class GPU_EXPORT QueryManager {
   // True if there are pending queries.
   bool HavePendingQueries();
 
+  GLES2Decoder* decoder() const {
+    return decoder_;
+  }
+
  private:
   void StartTracking(Query* query);
   void StopTracking(Query* query);
@@ -183,8 +187,8 @@ class GPU_EXPORT QueryManager {
   // used to emulate a query.
   GLenum AdjustTargetForEmulation(GLenum target);
 
-  // Used to validate shared memory.
-  CommonDecoder* decoder_;
+  // Used to validate shared memory and get GL errors.
+  GLES2Decoder* decoder_;
 
   bool use_arb_occlusion_query2_for_occlusion_query_boolean_;
   bool use_arb_occlusion_query_for_occlusion_query_boolean_;
diff --git a/gpu/command_buffer/service/query_manager_unittest.cc b/gpu/command_buffer/service/query_manager_unittest.cc
index bd2b84f..941b2e8 100644
--- a/gpu/command_buffer/service/query_manager_unittest.cc
+++ b/gpu/command_buffer/service/query_manager_unittest.cc
@@ -6,28 +6,20 @@
 #include "gpu/command_buffer/common/gl_mock.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 #include "gpu/command_buffer/service/cmd_buffer_engine.h"
-#include "gpu/command_buffer/service/common_decoder.h"
+#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
+#include "gpu/command_buffer/service/gles2_cmd_decoder_mock.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/test_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::_;
 using ::testing::InSequence;
+using ::testing::Return;
 using ::testing::SetArgumentPointee;
 
 namespace gpu {
 namespace gles2 {
 
-class MockDecoder : public CommonDecoder {
- public:
-  virtual ~MockDecoder() { }
-  MOCK_METHOD3(DoCommand, error::Error(
-     unsigned int command,
-     unsigned int arg_count,
-     const void* cmd_data));
-  MOCK_CONST_METHOD1(GetCommandName, const char* (unsigned int command_id));
-};
-
 class QueryManagerTest : public testing::Test {
  public:
   static const int32 kSharedMemoryId = 401;
@@ -48,7 +40,7 @@ class QueryManagerTest : public testing::Test {
     gl_.reset(new ::testing::StrictMock< ::gfx::MockGLInterface>());
     ::gfx::GLInterface::SetGLInterface(gl_.get());
     engine_.reset(new MockCommandBufferEngine());
-    decoder_.reset(new MockDecoder());
+    decoder_.reset(new MockGLES2Decoder());
     decoder_->set_engine(engine_.get());
     TestHelper::SetupFeatureInfoInitExpectations(
         gl_.get(),
@@ -90,7 +82,7 @@ class QueryManagerTest : public testing::Test {
 
   // Use StrictMock to make 100% sure we know how GL will be called.
   scoped_ptr< ::testing::StrictMock< ::gfx::MockGLInterface> > gl_;
-  scoped_ptr<MockDecoder> decoder_;
+  scoped_ptr<MockGLES2Decoder> decoder_;
   scoped_ptr<QueryManager> manager_;
 
  private:
@@ -469,6 +461,8 @@ TEST_F(QueryManagerTest, ExitWithPendingQuery) {
   QueueQuery(query.get(), kService1Id, kSubmitCount);
 }
 
+// Test that when based on ARB_occlusion_query2 we use GL_ANY_SAMPLES_PASSED_ARB
+// for GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT
 TEST_F(QueryManagerTest, ARBOcclusionQuery2) {
   const GLuint kClient1Id = 1;
   const GLuint kService1Id = 11;
@@ -501,6 +495,8 @@ TEST_F(QueryManagerTest, ARBOcclusionQuery2) {
   manager->Destroy(false);
 }
 
+// Test that when based on ARB_occlusion_query we use GL_SAMPLES_PASSED_ARB
+// for GL_ANY_SAMPLES_PASSED_EXT
 TEST_F(QueryManagerTest, ARBOcclusionQuery) {
   const GLuint kClient1Id = 1;
   const GLuint kService1Id = 11;
@@ -533,6 +529,41 @@ TEST_F(QueryManagerTest, ARBOcclusionQuery) {
   manager->Destroy(false);
 }
 
+TEST_F(QueryManagerTest, GetErrorQuery) {
+  const GLuint kClient1Id = 1;
+  const GLenum kTarget = GL_GET_ERROR_QUERY_CHROMIUM;
+  const uint32 kSubmitCount = 123;
+
+  TestHelper::SetupFeatureInfoInitExpectations(gl_.get(), "");
+  FeatureInfo::Ref feature_info(new FeatureInfo());
+  feature_info->Initialize("*");
+  scoped_ptr<QueryManager> manager(
+      new QueryManager(decoder_.get(), feature_info.get()));
+
+  QueryManager::Query* query = manager->CreateQuery(
+      kTarget, kClient1Id, kSharedMemoryId, kSharedMemoryOffset);
+  ASSERT_TRUE(query != NULL);
+
+  // Setup shared memory like client would.
+  QuerySync* sync = decoder_->GetSharedMemoryAs<QuerySync*>(
+      kSharedMemoryId, kSharedMemoryOffset, sizeof(*sync));
+  ASSERT_TRUE(sync != NULL);
+  sync->Reset();
+
+  EXPECT_TRUE(manager->BeginQuery(query));
+
+  EXPECT_CALL(*decoder_.get(), GetGLError())
+      .WillOnce(Return(GL_INVALID_ENUM))
+      .RetiresOnSaturation();
+
+  EXPECT_TRUE(manager->EndQuery(query, kSubmitCount));
+  EXPECT_FALSE(query->pending());
+
+  EXPECT_EQ(static_cast<GLuint>(GL_INVALID_ENUM), sync->result);
+
+  manager->Destroy(false);
+}
+
 }  // namespace gles2
 }  // namespace gpu
 
diff --git a/gpu/command_buffer/tests/gl_get_error_query_unittests.cc b/gpu/command_buffer/tests/gl_get_error_query_unittests.cc
new file mode 100644
index 0000000..a177044
--- /dev/null
+++ b/gpu/command_buffer/tests/gl_get_error_query_unittests.cc
@@ -0,0 +1,53 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
+#include "gpu/command_buffer/tests/gl_manager.h"
+#include "gpu/command_buffer/tests/gl_test_utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace gpu {
+
+class GetErrorQueryTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    gl_.Initialize(gfx::Size(2, 2));
+  }
+
+  virtual void TearDown() {
+    gl_.Destroy();
+  }
+
+  GLManager gl_;
+};
+
+TEST_F(GetErrorQueryTest, Basic) {
+  EXPECT_TRUE(GLTestHelper::HasExtension("GL_CHROMIUM_get_error_query"));
+
+  GLuint query = 0;
+  glGenQueriesEXT(1, &query);
+
+  GLuint query_status = 0;
+  GLuint result = 0;
+
+  glBeginQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM, query);
+  glEnable(GL_TEXTURE_2D);  // Generates an INVALID_ENUM error
+  glEndQueryEXT(GL_GET_ERROR_QUERY_CHROMIUM);
+
+  glFinish();
+
+  query_status = 0;
+  result = 0;
+  glGetQueryObjectuivEXT(query, GL_QUERY_RESULT_AVAILABLE_EXT, &result);
+  EXPECT_TRUE(result);
+  glGetQueryObjectuivEXT(query, GL_QUERY_RESULT_EXT, &query_status);
+  EXPECT_EQ(static_cast<uint32>(GL_INVALID_ENUM), query_status);
+}
+
+}  // namespace gpu
+
+
diff --git a/gpu/command_buffer_client.gypi b/gpu/command_buffer_client.gypi
index f007f97..97484f6 100644
--- a/gpu/command_buffer_client.gypi
+++ b/gpu/command_buffer_client.gypi
@@ -23,8 +23,6 @@
     'command_buffer/client/hash_tables.h',
     'command_buffer/client/mapped_memory.cc',
     'command_buffer/client/mapped_memory.h',
-    'command_buffer/client/query_tracker.cc',
-    'command_buffer/client/query_tracker.h',
     'command_buffer/client/ring_buffer.cc',
     'command_buffer/client/ring_buffer.h',
     'command_buffer/client/transfer_buffer.cc',
diff --git a/gpu/gpu.gyp b/gpu/gpu.gyp
index e87daae..1b8d54d 100644
--- a/gpu/gpu.gyp
+++ b/gpu/gpu.gyp
@@ -25,6 +25,8 @@
       'command_buffer/client/gles2_implementation.h',
       'command_buffer/client/program_info_manager.cc',
       'command_buffer/client/program_info_manager.h',
+      'command_buffer/client/query_tracker.cc',
+      'command_buffer/client/query_tracker.h',
       'command_buffer/client/share_group.cc',
       'command_buffer/client/share_group.h',
     ]
diff --git a/gpu/gpu_common.gypi b/gpu/gpu_common.gypi
index 6fa68294..d117fc0 100644
--- a/gpu/gpu_common.gypi
+++ b/gpu/gpu_common.gypi
@@ -231,10 +231,10 @@
       ],
       'sources': [
         '<@(gles2_c_lib_source_files)',
-        'command_buffer/tests/occlusion_query_unittests.cc',
         'command_buffer/tests/gl_bind_uniform_location_unittest.cc',
         'command_buffer/tests/gl_copy_texture_CHROMIUM_unittest.cc',
         'command_buffer/tests/gl_depth_texture_unittest.cc',
+        'command_buffer/tests/gl_get_error_query_unittests.cc',
         'command_buffer/tests/gl_manager.cc',
         'command_buffer/tests/gl_manager.h',
         'command_buffer/tests/gl_pointcoord_unittest.cc',
@@ -243,6 +243,7 @@
         'command_buffer/tests/gl_test_utils.h',
         'command_buffer/tests/gl_texture_mailbox_unittests.cc',
         'command_buffer/tests/gl_unittests.cc',
+        'command_buffer/tests/occlusion_query_unittests.cc',
       ],
     },
     {
diff --git a/third_party/khronos/GLES2/gl2ext.h b/third_party/khronos/GLES2/gl2ext.h
index c604c12..ee0da03 100644
--- a/third_party/khronos/GLES2/gl2ext.h
+++ b/third_party/khronos/GLES2/gl2ext.h
@@ -1985,6 +1985,15 @@ typedef void (GL_APIENTRYP PFNGLCOPYTEXTURECHROMIUM) (GLenum target, GLenum sour
 #define GL_COMMANDS_ISSUED_CHROMIUM 0x84F2
 #endif
 
+/* GL_CHROMIUM_get_error_query */
+/* Exposes GL_CHROMIUM_get_error_query.
+ */
+#ifndef GL_CHROMIUM_get_error_query
+#define GL_CHROMIUM_get_error_query 1
+// TODO(gman): Get official numbers for these constants.
+#define GL_GET_ERROR_QUERY_CHROMIUM 0x84F3
+#endif
+
 /* GL_CHROMIUM_texture_mailbox */
 #ifndef GL_CHROMIUM_texture_mailbox
 #define GL_CHROMIUM_texture_mailbox 1
diff --git a/third_party/khronos/README.chromium b/third_party/khronos/README.chromium
index 1fa97c6..bbdba9c 100644
--- a/third_party/khronos/README.chromium
+++ b/third_party/khronos/README.chromium
@@ -23,5 +23,6 @@ GLES2/gl2ext.h
  - Added GL_CHROMIUM_command_buffer_query
  - Added GL_CHROMIUM_copy_texture
  - Added GL_CHROMIUM_bind_uniform_location
+ - Added GL_CHROMIUM_get_error_query
 EGL/eglplatform.h
  - Added EGLNative*Type for Mac.