Fix EGL configs with GLSurfaceOzoneSurfaceless.

ui/gl/gl_surface_egl.cc

Index: ui/gl/gl_surface_egl.cc
diff --git a/ui/gl/gl_surface_egl.cc b/ui/gl/gl_surface_egl.cc
index 8c3ed9fa9b876ae50090713841424278b44db784..a444ab1fb45c4bf7754de4c9989742c00cdae0b7 100644
--- a/ui/gl/gl_surface_egl.cc
+++ b/ui/gl/gl_surface_egl.cc
@@ -251,11 +251,12 @@ bool ValidateEglConfig(EGLDisplay display,
   return true;
 }
 
-EGLConfig ChooseConfig(GLSurface::Format format) {
-  static std::map<GLSurface::Format, EGLConfig> config_map;
+EGLConfig ChooseConfig(GLSurface::Format format, bool is_surfaceless) {
+  static std::map<std::pair<GLSurface::Format, bool>, EGLConfig> config_map;

[no sievers, 2016/03/08 22:02:00]

It seems odd that surfaceless even cares about |Format|.
We could also add a FORMAT_SURFACELESS or something for Format instead. wdyt?

[kylechar, 2016/03/09 15:07:30]

This is all sort of black magic to me (and documentation is very sparse). The
EGL config for surfaceless GLSurfaces gets used when creating a context. It
would sort of make sense that EGL config ARGB should match the match whatever
framebuffer object the context is going to be rendering into, so maybe
GLSurface::Format does matter?

On the other hand maybe I'm just totally misunderstanding things here? The only
place SURFACE_RGB565 is actually ever set is with PbufferGLSurfaceEGL.

https://code.google.com/p/chromium/codesearch#chromium/src/ui/gl/gl_surface_e...

That means it can't matter for surfaceless (or it does matter but all
surfaceless contexts are drawing into ARGB8888 framebuffers?) I guess adding a
new format SURFACE_SURFACELESS should work.

 
-  if (config_map.find(format) != config_map.end()) {
-    return config_map[format];
+  auto config_type = std::make_pair(format, is_surfaceless);
+  if (config_map.find(config_type) != config_map.end()) {
+    return config_map[config_type];
   }
 
   // Choose an EGL configuration.
@@ -283,6 +284,9 @@ EGLConfig ChooseConfig(GLSurface::Format format) {
   }
 #endif
 
+  EGLint surface_type =
+      is_surfaceless ? EGL_DONT_CARE : EGL_WINDOW_BIT | EGL_PBUFFER_BIT;
+
   EGLint config_attribs_8888[] = {
     EGL_BUFFER_SIZE, buffer_size,
     EGL_ALPHA_SIZE, alpha_size,
@@ -290,7 +294,7 @@ EGLConfig ChooseConfig(GLSurface::Format format) {
     EGL_GREEN_SIZE, 8,
     EGL_RED_SIZE, 8,
     EGL_RENDERABLE_TYPE, renderable_type,
-    EGL_SURFACE_TYPE, EGL_WINDOW_BIT | EGL_PBUFFER_BIT,
+    EGL_SURFACE_TYPE, surface_type,
     EGL_NONE
   };
 
@@ -301,7 +305,7 @@ EGLConfig ChooseConfig(GLSurface::Format format) {
     EGL_GREEN_SIZE, 6,
     EGL_RED_SIZE, 5,
     EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
-    EGL_SURFACE_TYPE, EGL_WINDOW_BIT | EGL_PBUFFER_BIT,
+    EGL_SURFACE_TYPE, surface_type,
     EGL_NONE
   };
   if (format == GLSurface::SURFACE_RGB565) {
@@ -374,7 +378,7 @@ EGLConfig ChooseConfig(GLSurface::Format format) {
       }
     }
   }
-  config_map[format] = config;
+  config_map[config_type] = config;
   return config;
 }
 
@@ -506,7 +510,7 @@ EGLDisplay GLSurfaceEGL::GetDisplay() {
 
 EGLConfig GLSurfaceEGL::GetConfig() {
   if (!config_) {
-    config_ = ChooseConfig(format_);
+    config_ = ChooseConfig(format_, IsSurfaceless());
   }
   return config_;
 }