skia: Add ANGLE with GL backend to nanobench/DM

src/gpu/gl/angle/SkANGLEGLContext.cpp

Index: src/gpu/gl/angle/SkANGLEGLContext.cpp
diff --git a/src/gpu/gl/angle/SkANGLEGLContext.cpp b/src/gpu/gl/angle/SkANGLEGLContext.cpp
index 8ebdcb661eacc69587feaa06ae25f919c2ea309b..64a3bdec74381365db58936fe4d43db3a424bc16 100644
--- a/src/gpu/gl/angle/SkANGLEGLContext.cpp
+++ b/src/gpu/gl/angle/SkANGLEGLContext.cpp
@@ -15,8 +15,9 @@
 #define EGL_PLATFORM_ANGLE_TYPE_ANGLE           0x3203
 #define EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE      0x3207
 #define EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE     0x3208
+#define EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE    0x320D
 
-void* SkANGLEGLContext::GetD3DEGLDisplay(void* nativeDisplay) {
+void* SkANGLEGLContext::GetD3DEGLDisplay(void* nativeDisplay, bool useGLBackend) {
     PFNEGLGETPLATFORMDISPLAYEXTPROC eglGetPlatformDisplayEXT;
     eglGetPlatformDisplayEXT =
         (PFNEGLGETPLATFORMDISPLAYEXTPROC)eglGetProcAddress("eglGetPlatformDisplayEXT");
@@ -25,29 +26,44 @@ void* SkANGLEGLContext::GetD3DEGLDisplay(void* nativeDisplay) {
         return eglGetDisplay(static_cast<EGLNativeDisplayType>(nativeDisplay));
     }
 
-    // Try for an ANGLE D3D11 context, fall back to D3D9.
-    EGLint attribs[2][3] = {
-        {
-            EGL_PLATFORM_ANGLE_TYPE_ANGLE,
-            EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE,
-            EGL_NONE
-        },
-        {
-            EGL_PLATFORM_ANGLE_TYPE_ANGLE,
-            EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE,
-            EGL_NONE
-        }
-    };
-
     EGLDisplay display = EGL_NO_DISPLAY;
-    for (int i = 0; i < 2 && display == EGL_NO_DISPLAY; ++i) {
+    if (useGLBackend) {
+        // Try for an ANGLE D3D11 context, fall back to D3D9.
+        EGLint attribs[3] = {
+              EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+              EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE,
+              EGL_NONE
+        };
         display = eglGetPlatformDisplayEXT(EGL_PLATFORM_ANGLE_ANGLE,
-                                            nativeDisplay, attribs[i]);
+                                            nativeDisplay, attribs);
+    } else {
+        // Try for an ANGLE D3D11 context, fall back to D3D9, and finally GL.
+        EGLint attribs[3][3] = {
+            {
+                EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+                EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE,
+                EGL_NONE
+            },
+            {
+                EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+                EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE,
+                EGL_NONE
+            },
+            {
+                EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+                EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE,
+                EGL_NONE
+            }
+        };
+        for (int i = 0; i < 3 && display == EGL_NO_DISPLAY; ++i) {
+            display = eglGetPlatformDisplayEXT(EGL_PLATFORM_ANGLE_ANGLE,
+                                                nativeDisplay, attribs[i]);
+        }
     }
     return display;
 }
 
-SkANGLEGLContext::SkANGLEGLContext()
+SkANGLEGLContext::SkANGLEGLContext(bool useGLBackend)
     : fContext(EGL_NO_CONTEXT)
     , fDisplay(EGL_NO_DISPLAY)
     , fSurface(EGL_NO_SURFACE) {
@@ -63,7 +79,7 @@ SkANGLEGLContext::SkANGLEGLContext()
         EGL_NONE
     };
 
-    fDisplay = GetD3DEGLDisplay(EGL_DEFAULT_DISPLAY);
+    fDisplay = GetD3DEGLDisplay(EGL_DEFAULT_DISPLAY, useGLBackend);
     if (EGL_NO_DISPLAY == fDisplay) {
         SkDebugf("Could not create EGL display!");
         return;