prepare skia for shared library build on android

platform_tools/android/launcher/skia_launcher.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <dlfcn.h>
 #include <stdio.h>
 
@@ skipping 10 matching lines @@
         return true;
     }
     return false;
 }
 
 int launch_app(int (*app_main)(int, const char**), int argc,
         const char** argv) {
     return (*app_main)(argc, argv);
 }
 
+void* load_library(const char** argv, const char* libraryName)
+{
+     // attempt to lookup the location of the shared libraries
+    char libraryLocation[100];
+    sprintf(libraryLocation, "%s/lib/lib%s.so", argv[0], libraryName);
+    if (!file_exists(libraryLocation)) {
+        printf("ERROR: Unable to find the appropriate library in the Skia App.\n");
+        printf("ERROR: Did you provide the correct program_name?\n");
+        usage(argv[0]);
+        return NULL;
+    }
+
+    // load the appropriate library
+    void* appLibrary = dlopen(libraryLocation, RTLD_LOCAL | RTLD_LAZY);
+    if (!appLibrary) {
+        printf("ERROR: Unable to open the shared library.\n");
+        printf("ERROR: %s", dlerror());
+        return NULL;
+    }
+
+    return appLibrary;
+}
+
 int main(int argc, const char** argv) {
 
     // check that the program name was specified
     if (argc < 2) {
         printf("ERROR: No program_name was specified\n");
         usage(argv[0]);
         return -1;
     }
 
     // attempt to lookup the location of the skia app
     const char* appLocation = "/data/data/com.skia";
     if (!file_exists(appLocation)) {
         printf("ERROR: Unable to find the com.skia app on the device.\n");
         return -1;
     }
 
-    // attempt to lookup the location of the shared libraries
-    char libraryLocation[100];
-    sprintf(libraryLocation, "%s/lib/lib%s.so", appLocation, argv[1]);
-    if (!file_exists(libraryLocation)) {
-        printf("ERROR: Unable to find the appropriate library in the Skia App.\n");
-        printf("ERROR: Did you provide the correct program_name?\n");
-        usage(argv[0]);
+    // load the local skia shared library
+    void* skiaLibrary = load_library(argv, "libskia_android.so");
+    if (NULL == skiaLibrary)
+    {
         return -1;
     }
 
     // load the appropriate library
-    void* appLibrary = dlopen(libraryLocation, RTLD_LOCAL | RTLD_LAZY);
-    if (!appLibrary) {
-        printf("ERROR: Unable to open the shared library.\n");
-        printf("ERROR: %s", dlerror());
+    void* appLibrary = load_library(argv, argv[1]);
+    if (NULL == appLibrary) {
         return -1;
     }
 
     // find the address of the main function
     int (*app_main)(int, const char**);
     *(void **) (&app_main) = dlsym(appLibrary, "main");
 
     if (!app_main) {
         printf("ERROR: Unable to load the main function of the selected program.\n");
         printf("ERROR: %s\n", dlerror());
         return -1;
     }
 
     // find the address of the SkPrintToConsole function
     void (*app_SkDebugToStdOut)(bool);
     *(void **) (&app_SkDebugToStdOut) = dlsym(appLibrary, "AndroidSkDebugToStdOut");
 
     if (app_SkDebugToStdOut) {
         (*app_SkDebugToStdOut)(true);
     } else {
         printf("WARNING: Unable to redirect output to the console.\n");
         printf("WARNING: %s\n", dlerror());
     }
 
     // pass all additional arguments to the main function
     return launch_app(app_main, argc - 1, ++argv);
 }