Support mesa config in render_pictures.

tools/PictureRenderer.h

Index: tools/PictureRenderer.h
===================================================================
--- tools/PictureRenderer.h	(revision 12915)
+++ tools/PictureRenderer.h	(working copy)
@@ -69,6 +69,9 @@
 #if SK_ANGLE
         kAngle_DeviceType,
 #endif
+#if SK_MESA
+        kMesa_DeviceType,
+#endif
         kBitmap_DeviceType,
 #if SK_SUPPORT_GPU
         kGPU_DeviceType,
@@ -177,7 +180,12 @@
                 glContextType = GrContextFactory::kANGLE_GLContextType;
                 break;
 #endif
+#if SK_MESA
+            case kMesa_DeviceType:
+                glContextType = GrContextFactory::kMESA_GLContextType;
+                break;
 #endif
+#endif
             default:
                 // Invalid device type.
                 return false;
@@ -256,6 +264,11 @@
                 config.append("_angle");
                 break;
 #endif
+#if SK_MESA
+            case kMesa_DeviceType:
+                config.append("_mesa");
+                break;
+#endif
             default:
                 // Assume that no extra info means bitmap.
                 break;
@@ -272,7 +285,11 @@
                 // fall through
 #if SK_ANGLE
             case kAngle_DeviceType:
+                // fall through
 #endif
+#if SK_MESA
+            case kMesa_DeviceType:
+#endif
                 return true;
             default:
                 return false;
@@ -291,6 +308,11 @@
                 glContextType = GrContextFactory::kANGLE_GLContextType;
                 break;
 #endif
+#if SK_MESA
+            case kMesa_DeviceType:
+                glContextType = GrContextFactory::kMESA_GLContextType;
+                break;
+#endif
             default:
                 return NULL;
         }