Add more error printing to know why command buffer lib failed to load.

tools/gpu/gl/command_buffer/GLTestContext_command_buffer.cpp

 
 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMutex.h"
 #include "SkOnce.h"
@@ skipping 70 matching lines @@
 static MakeCurrentProc gfMakeCurrent = nullptr;
 static SwapBuffersProc gfSwapBuffers = nullptr;
 static GetProcAddressProc gfGetProcAddress = nullptr;
 
 static void* gLibrary = nullptr;
 static bool gfFunctionsLoadedSuccessfully = false;
 
 namespace {
 static void load_command_buffer_functions() {
     if (!gLibrary) {
+        static constexpr const char* libName =
 #if defined _WIN32
-        gLibrary = DynamicLoadLibrary("command_buffer_gles2.dll");
+        "command_buffer_gles2.dll";
 #elif defined SK_BUILD_FOR_MAC
-        gLibrary = DynamicLoadLibrary("libcommand_buffer_gles2.dylib");
+        "libcommand_buffer_gles2.dylib";
 #else
-        gLibrary = DynamicLoadLibrary("libcommand_buffer_gles2.so");
+        "libcommand_buffer_gles2.so";
 #endif // defined _WIN32
+        gLibrary = DynamicLoadLibrary(libName);
         if (gLibrary) {
             gfGetDisplay = (GetDisplayProc)GetProcedureAddress(gLibrary, "eglGetDisplay");
             gfInitialize = (InitializeProc)GetProcedureAddress(gLibrary, "eglInitialize");
             gfTerminate = (TerminateProc)GetProcedureAddress(gLibrary, "eglTerminate");
             gfChooseConfig = (ChooseConfigProc)GetProcedureAddress(gLibrary, "eglChooseConfig");
             gfGetConfigAttrib = (GetConfigAttrib)GetProcedureAddress(gLibrary, "eglGetConfigAttrib");
             gfCreateWindowSurface = (CreateWindowSurfaceProc)GetProcedureAddress(gLibrary, "eglCreateWindowSurface");
             gfCreatePbufferSurface = (CreatePbufferSurfaceProc)GetProcedureAddress(gLibrary, "eglCreatePbufferSurface");
             gfDestroySurface = (DestroySurfaceProc)GetProcedureAddress(gLibrary, "eglDestroySurface");
             gfCreateContext = (CreateContextProc)GetProcedureAddress(gLibrary, "eglCreateContext");
             gfDestroyContext = (DestroyContextProc)GetProcedureAddress(gLibrary, "eglDestroyContext");
             gfMakeCurrent = (MakeCurrentProc)GetProcedureAddress(gLibrary, "eglMakeCurrent");
             gfSwapBuffers = (SwapBuffersProc)GetProcedureAddress(gLibrary, "eglSwapBuffers");
             gfGetProcAddress = (GetProcAddressProc)GetProcedureAddress(gLibrary, "eglGetProcAddress");
 
             gfFunctionsLoadedSuccessfully = gfGetDisplay && gfInitialize && gfTerminate &&
                                             gfChooseConfig && gfCreateWindowSurface &&
                                             gfCreatePbufferSurface && gfDestroySurface &&
                                             gfCreateContext && gfDestroyContext && gfMakeCurrent &&
                                             gfSwapBuffers && gfGetProcAddress;
 
+        } else {
+            SkDebugf("Could not load %s.\n", libName);
         }
     }
 }
 
 static GrGLFuncPtr command_buffer_get_gl_proc(void* ctx, const char name[]) {
     if (!gfFunctionsLoadedSuccessfully) {
         return nullptr;
     }
     return gfGetProcAddress(name);
 }
@@ skipping 204 matching lines @@
     return result;
 }
 
 int CommandBufferGLTestContext::getSampleCount() {
     EGLint result = 0;
     gfGetConfigAttrib(fDisplay, static_cast<EGLConfig>(fConfig), EGL_SAMPLES, &result);
     return result;
 }
 
 }  // namespace sk_gpu_test