Use D3D11 backend for ANGLE when available.

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 2cff750fa041d5b1dcab3c9200c23d0bea6a80ed..9470bf036041bf0b0b5c4ddae935b228ff50065c 100644
--- a/src/gpu/gl/angle/SkANGLEGLContext.cpp
+++ b/src/gpu/gl/angle/SkANGLEGLContext.cpp
@@ -8,15 +8,50 @@
 
 #include "gl/angle/SkANGLEGLContext.h"
 
+#define EGL_PLATFORM_ANGLE_ANGLE                0x3201
+#define EGL_PLATFORM_ANGLE_TYPE_ANGLE           0x3202
+#define EGL_PLATFORM_ANGLE_TYPE_D3D9_ANGLE      0x3206
+#define EGL_PLATFORM_ANGLE_TYPE_D3D11_ANGLE     0x3207
+
+EGLDisplay SkANGLEGLContext::GetD3DEGLDisplay(EGLNativeDisplayType nativeDisplay) {
+
+    typedef EGLDisplay (*EGLGetPlatformDisplayEXT)(EGLenum platform,
+                                                   void *native_display,
+                                                   const EGLint *attrib_list);
+    EGLGetPlatformDisplayEXT eglGetPlatformDisplayEXT;
+    eglGetPlatformDisplayEXT =
+        (EGLGetPlatformDisplayEXT) eglGetProcAddress("eglGetPlatformDisplayEXT");
+
+    if (!eglGetPlatformDisplayEXT) {
+        return eglGetDisplay(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) {
+        display = eglGetPlatformDisplayEXT(EGL_PLATFORM_ANGLE_ANGLE,
+                                            nativeDisplay, attribs[i]);
+    }
+    return display;
+}
+
 SkANGLEGLContext::SkANGLEGLContext()
     : fContext(EGL_NO_CONTEXT)
     , fDisplay(EGL_NO_DISPLAY)
     , fSurface(EGL_NO_SURFACE) {
-    fDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-
-    EGLint majorVersion;
-    EGLint minorVersion;
-    eglInitialize(fDisplay, &majorVersion, &minorVersion);
 
     EGLint numConfigs;
     static const EGLint configAttribs[] = {
@@ -29,6 +64,16 @@ SkANGLEGLContext::SkANGLEGLContext()
         EGL_NONE
     };
 
+    fDisplay = GetD3DEGLDisplay(EGL_DEFAULT_DISPLAY);
+    if (EGL_NO_DISPLAY == fDisplay) {
+        SkDebugf("Could not create EGL display!");
+        return;
+    }
+
+    EGLint majorVersion;
+    EGLint minorVersion;
+    eglInitialize(fDisplay, &majorVersion, &minorVersion);
+
     EGLConfig surfaceConfig;
     eglChooseConfig(fDisplay, configAttribs, &surfaceConfig, 1, &numConfigs);
 
@@ -40,10 +85,11 @@ SkANGLEGLContext::SkANGLEGLContext()
 
 
     static const EGLint surfaceAttribs[] = {
-            EGL_WIDTH, 1,
-            EGL_HEIGHT, 1,
-            EGL_NONE
-        };
+        EGL_WIDTH, 1,
+        EGL_HEIGHT, 1,
+        EGL_NONE
+    };
+
     fSurface = eglCreatePbufferSurface(fDisplay, surfaceConfig, surfaceAttribs);
 
     eglMakeCurrent(fDisplay, fSurface, fSurface, fContext);