Revert 254571 "Remove the enable-d3d11 flag so that d3d11 is ena..."

Bug in D3D 11 runtime. Reverting on behalf of geofflang@chromium.org

> Remove the enable-d3d11 flag so that d3d11 is enabled by default.
> 
> BUG=346394
> R=kbr@chromium.org
> 
> Review URL: https://codereview.chromium.org/177003009

TBR=bajones@chromium.org

Review URL: https://codereview.chromium.org/189543017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256018 0039d316-1c4b-4281-b951-d872f2087c98

chrome/app/generated_resources.grd

@@ -6110,6 +6110,12 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_ENABLE_WEBGL_DESCRIPTION" desc="Description for the flag to enable WebGL.">
         Enabling this option allows web applications to access the WebGL API.
       </message>
+      <message name="IDS_FLAGS_ENABLE_D3D11_NAME" desc="Name of the 'Enable D3D11' lab.">
+        Enable D3D11
+      </message>
+      <message name="IDS_FLAGS_ENABLE_D3D11_DESCRIPTION" desc="Description for the flag to enable D3D11.">
+        Enabling this option allows the use of Direct3D 11 on configurations that support it.
+      </message>
       <message name="IDS_FLAGS_ENABLE_WEBGL_DRAFT_EXTENSIONS_NAME" desc="Name of the 'Enable WebGL Draft Extensions' flag.">
         Enable WebGL Draft Extensions
       </message>

chrome/browser/about_flags.cc

@@ -520,6 +520,13 @@ const Experiment kExperiments[] = {
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kDisableExperimentalWebGL)
   },
+  {
+    "enable-d3d11",
+    IDS_FLAGS_ENABLE_D3D11_NAME,
+    IDS_FLAGS_ENABLE_D3D11_DESCRIPTION,
+    kOsWin,
+    SINGLE_VALUE_TYPE(switches::kEnableD3D11)
+  },
   {
     "disable-webrtc",
     IDS_FLAGS_DISABLE_WEBRTC_NAME,

content/test/gpu/page_sets/pixel_tests.json

@@ -41,7 +41,7 @@
             "timeout": 30
         }
       ],
-      "revision": 3,
+      "revision": 2,
       "test_rect": [0, 0, 400, 300]
     }
   ]

ui/gl/gl_surface_egl.cc

@@ -131,7 +131,8 @@ bool GLSurfaceEGL::InitializeOneOff() {
   g_native_display = base::MessagePumpForUI::GetDefaultXDisplay();
 #elif defined(OS_WIN)
   g_native_display = EGL_DEFAULT_DISPLAY;
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11)) {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11) &&
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableD3D11)) {
     g_native_display = EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
   }
 #elif defined(USE_OZONE)

ui/gl/gl_switches.cc

@@ -18,6 +18,9 @@ const char kGLImplementationMockName[]        = "mock";
 
 namespace switches {
 
+// Enables use of D3D11 when available.
+const char kEnableD3D11[]                   = "enable-d3d11";
+
 // Disables use of D3D11.
 const char kDisableD3D11[]                  = "disable-d3d11";
 
@@ -76,6 +79,7 @@ const char kUseGpuInTests[] = "use-gpu-in-tests";
 // to read it in the GPU process, else don't add it.
 const char* kGLSwitchesCopiedFromGpuProcessHost[] = {
   kDisableGpuVsync,
+  kEnableD3D11,
   kDisableD3D11,
   kEnableGPUServiceLogging,
   kEnableGPUServiceTracing,

ui/gl/gl_switches.h

@@ -23,6 +23,7 @@ extern const char kGLImplementationMockName[];
 
 namespace switches {
 
+GL_EXPORT extern const char kEnableD3D11[];
 GL_EXPORT extern const char kDisableD3D11[];
 GL_EXPORT extern const char kDisableGpuVsync[];
 GL_EXPORT extern const char kEnableGPUServiceLogging[];