Disable Canvas2DAllowed for OS_LINUX, it times out on Linux debug shared build bot.

chrome/test/gpu/gpu_feature_browsertest.cc

 // Copyright (c) 2011 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 "base/command_line.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/test/trace_event_analyzer.h"
 #include "base/version.h"
@@ skipping 139 matching lines @@
   SetupBlacklist(json_blacklist);
   GpuFeatureFlags flags = GpuDataManager::GetInstance()->GetGpuFeatureFlags();
   EXPECT_EQ(
       flags.flags(),
       static_cast<uint32>(GpuFeatureFlags::kGpuFeatureWebgl));
 
   const FilePath url(FILE_PATH_LITERAL("feature_webgl.html"));
   RunTest(url, EXPECT_NO_GPU_PROCESS);
 }
 
+#if defined(OS_LINUX)
+// http://crbug.com/104142
+#define Canvas2DAllowed DISABLED_Canvas2DAllowed
+#endif
 IN_PROC_BROWSER_TEST_F(GpuFeatureTest, Canvas2DAllowed) {
   GpuFeatureFlags flags = GpuDataManager::GetInstance()->GetGpuFeatureFlags();
   EXPECT_EQ(flags.flags(), 0u);
 
   const FilePath url(FILE_PATH_LITERAL("feature_canvas2d.html"));
   RunTest(url, EXPECT_GPU_SWAP_BUFFERS);
 }
 
 IN_PROC_BROWSER_TEST_F(GpuFeatureTest, Canvas2DBlocked) {
   const std::string json_blacklist =
@@ skipping 14 matching lines @@
   EXPECT_EQ(
       flags.flags(),
       static_cast<uint32>(GpuFeatureFlags::kGpuFeatureAccelerated2dCanvas));
 
   const FilePath url(FILE_PATH_LITERAL("feature_canvas2d.html"));
   RunTest(url, EXPECT_NO_GPU_PROCESS);
 }
 
 }  // namespace anonymous