Allow compiling PDFium without V8.

Original patch from issue 1391843004 at patchset 1
(http://crrev.com/1391843004#ps1)

Introduce a pdf_enable_v8 GYP variable, which controls a
corresponding PDF_ENABLE_V8 #define, and bring in the real
JS library when set. Otherwise, link against a stub JS
runtime.

BUG=pdfium:211
R=dml@google.com, jochen@chromium.org, thestig@chromium.org

Review URL: https://codereview.chromium.org/1395733006 .

3 files changed, 47 insertions, 8 deletions

diff --git a/samples/BUILD.gn b/samples/BUILD.gn
index 6f4518c17e..5749de90f1 100644
--- a/samples/BUILD.gn
+++ b/samples/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("../pdfium.gni")
+
 group("samples") {
   deps = [
     ":pdfium_test",
@@ -15,6 +17,11 @@ config("pdfium_samples_config") {
     "PNGPREFIX_H",
     "PNG_USE_READ_MACROS",
   ]
+  if (pdf_enable_v8) {
+    defines += [
+      "PDF_ENABLE_V8",
+    ]
+  }
 }
 
 executable("pdfium_test") {
@@ -28,13 +35,17 @@ executable("pdfium_test") {
     # always link this binary against the bundled one for consistency
     # of results across platforms.
     "//third_party/pdfium/third_party:fx_freetype",
-    "//v8:v8_libplatform",
     ":fx_lpng",
   ]
-  include_dirs = [
-    "//v8",
-    "//v8/include",
-  ]
+  if (pdf_enable_v8) {
+    deps += [
+      "//v8:v8_libplatform",
+    ]
+    include_dirs = [
+      "//v8",
+      "//v8/include",
+    ]
+  }
   configs += [ ":pdfium_samples_config" ]
 }
 
diff --git a/samples/pdfium_test.cc b/samples/pdfium_test.cc
index 74e797b944..f15e19c75b 100644
--- a/samples/pdfium_test.cc
+++ b/samples/pdfium_test.cc
@@ -19,8 +19,10 @@
 #include "../public/fpdf_text.h"
 #include "../public/fpdfview.h"
 #include "image_diff_png.h"
+#ifdef PDF_ENABLE_V8
 #include "v8/include/libplatform/libplatform.h"
 #include "v8/include/v8.h"
+#endif
 
 #ifdef _WIN32
 #define snprintf _snprintf
@@ -79,6 +81,7 @@ static char* GetFileContents(const char* filename, size_t* retlen) {
   return buffer;
 }
 
+#ifdef PDF_ENABLE_V8
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 // Returns the full path for an external V8 data file based on either
 // the currect exectuable path or an explicit override.
@@ -116,6 +119,7 @@ static bool GetExternalData(const Options& options,
   return true;
 }
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
+#endif  // PDF_ENABLE_V8
 
 static bool CheckDimensions(int stride, int width, int height) {
   if (stride < 0 || width < 0 || height < 0)
@@ -373,6 +377,7 @@ bool ParseCommandLine(const std::vector<std::string>& args,
       options->output_format = OUTPUT_BMP;
     }
 #endif  // _WIN32
+#ifdef PDF_ENABLE_V8
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
     else if (cur_arg.size() > 10 && cur_arg.compare(0, 10, "--bin-dir=") == 0) {
       if (!options->bin_directory.empty()) {
@@ -382,6 +387,7 @@ bool ParseCommandLine(const std::vector<std::string>& args,
       options->bin_directory = cur_arg.substr(10);
     }
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
+#endif  // PDF_ENABLE_V8
     else if (cur_arg.size() > 8 && cur_arg.compare(0, 8, "--scale=") == 0) {
       if (!options->scale_factor_as_string.empty()) {
         fprintf(stderr, "Duplicate --scale argument\n");
@@ -595,6 +601,7 @@ int main(int argc, const char* argv[]) {
     return 1;
   }
 
+#ifdef PDF_ENABLE_V8
   v8::V8::InitializeICU();
   v8::Platform* platform = v8::platform::CreateDefaultPlatform();
   v8::V8::InitializePlatform(platform);
@@ -615,6 +622,7 @@ int main(int argc, const char* argv[]) {
   v8::V8::SetNativesDataBlob(&natives);
   v8::V8::SetSnapshotDataBlob(&snapshot);
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
+#endif  // PDF_ENABLE_V8
 
   FPDF_LIBRARY_CONFIG config;
   config.version = 2;
@@ -649,8 +657,10 @@ int main(int argc, const char* argv[]) {
   }
 
   FPDF_DestroyLibrary();
+#ifdef PDF_ENABLE_V8
   v8::V8::ShutdownPlatform();
   delete platform;
+#endif  // PDF_ENABLE_V8
 
   return 0;
 }
diff --git a/samples/samples.gyp b/samples/samples.gyp
index 4b6c16bf2e..496a274da7 100644
--- a/samples/samples.gyp
+++ b/samples/samples.gyp
@@ -3,6 +3,9 @@
 # found in the LICENSE file.
 
 {
+  'variables': {
+    'pdf_enable_v8%': 1,
+  },
   'target_defaults': {
     'defines' : [
       'PNG_PREFIX',
@@ -11,8 +14,17 @@
     ],
     'include_dirs': [
       '<(DEPTH)',
-      '<(DEPTH)/v8',
-      '<(DEPTH)/v8/include',
+    ],
+    'conditions': [
+      ['pdf_enable_v8==1', {
+        'defines': [
+          'PDF_ENABLE_V8',
+        ],
+        'include_dirs': [
+          '<(DEPTH)/v8',
+          '<(DEPTH)/v8/include',
+        ],
+      }],
     ],
   },
   'targets': [
@@ -26,7 +38,6 @@
         # always link this binary against the bundled one for consistency
         # of results across platforms.
         '../third_party/third_party.gyp:fx_freetype',
-        '<(DEPTH)/v8/tools/gyp/v8.gyp:v8_libplatform',
       ],
       'sources': [
         'pdfium_test.cc',
@@ -37,6 +48,13 @@
           '-lfreetype',
         ],
       },
+      'conditions': [
+        ['pdf_enable_v8==1', {
+          'dependencies': [
+            '<(DEPTH)/v8/tools/gyp/v8.gyp:v8_libplatform',
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'pdfium_diff',