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, 158 insertions, 6 deletions

diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index 0bf6426b66..b050e033cd 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -14,7 +14,7 @@
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_mgr.h"
 #include "../include/fsdk_rendercontext.h"
-#include "../include/jsapi/fxjs_v8.h"
+#include "../include/javascript/IJavaScript.h"
 
 CPDF_CustomAccess::CPDF_CustomAccess(FPDF_FILEACCESS* pFileAccess) {
   if (pFileAccess)
@@ -110,10 +110,8 @@ DLLEXPORT void STDCALL FPDF_InitLibraryWithConfig(
     pModuleMgr->LoadEmbeddedCNS1CMaps();
     pModuleMgr->LoadEmbeddedKorea1CMaps();
   }
-  if (cfg && cfg->version >= 2) {
-    FXJS_Initialize(cfg->m_v8EmbedderSlot,
-                    reinterpret_cast<v8::Isolate*>(cfg->m_pIsolate));
-  }
+  if (cfg && cfg->version >= 2)
+    IJS_Runtime::Initialize(cfg->m_v8EmbedderSlot, cfg->m_pIsolate);
 }
 
 DLLEXPORT void STDCALL FPDF_DestroyLibrary() {
diff --git a/fpdfsdk/src/javascript/JS_Runtime.cpp b/fpdfsdk/src/javascript/JS_Runtime.cpp
index 83e2c9af2a..069edc5cd6 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.cpp
+++ b/fpdfsdk/src/javascript/JS_Runtime.cpp
@@ -27,7 +27,10 @@
 #include "report.h"
 #include "util.h"
 
-/* ------------------------------ CJS_Runtime ------------------------------ */
+// static
+void IJS_Runtime::Initialize(unsigned int slot, void* isolate) {
+  FXJS_Initialize(slot, reinterpret_cast<v8::Isolate*>(isolate));
+}
 
 // static
 IJS_Runtime* IJS_Runtime::Create(CPDFDoc_Environment* pEnv) {
diff --git a/fpdfsdk/src/javascript/JS_Runtime_Stub.cpp b/fpdfsdk/src/javascript/JS_Runtime_Stub.cpp
new file mode 100644
index 0000000000..2c5e625fdc
--- /dev/null
+++ b/fpdfsdk/src/javascript/JS_Runtime_Stub.cpp
@@ -0,0 +1,151 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "../../../third_party/base/nonstd_unique_ptr.h"
+#include "../../include/fsdk_mgr.h"  // For CPDFDoc_Environment.
+#include "../../include/javascript/IJavaScript.h"
+
+class CJS_ContextStub final : public IJS_Context {
+ public:
+  CJS_ContextStub() {}
+  ~CJS_ContextStub() override {}
+
+  // IJS_Context:
+  FX_BOOL RunScript(const CFX_WideString& script,
+                    CFX_WideString& info) override {
+    return FALSE;
+  }
+
+  void OnApp_Init() override {}
+  void OnDoc_Open(CPDFSDK_Document* pDoc,
+                  const CFX_WideString& strTargetName) override {}
+  void OnDoc_WillPrint(CPDFSDK_Document* pDoc) override {}
+  void OnDoc_DidPrint(CPDFSDK_Document* pDoc) override {}
+  void OnDoc_WillSave(CPDFSDK_Document* pDoc) override {}
+  void OnDoc_DidSave(CPDFSDK_Document* pDoc) override {}
+  void OnDoc_WillClose(CPDFSDK_Document* pDoc) override {}
+  void OnPage_Open(CPDFSDK_Document* pTarget) override {}
+  void OnPage_Close(CPDFSDK_Document* pTarget) override {}
+  void OnPage_InView(CPDFSDK_Document* pTarget) override {}
+  void OnPage_OutView(CPDFSDK_Document* pTarget) override {}
+  void OnField_MouseDown(FX_BOOL bModifier,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget) override {}
+  void OnField_MouseEnter(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDF_FormField* pTarget) override {}
+  void OnField_MouseExit(FX_BOOL bModifier,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget) override {}
+  void OnField_MouseUp(FX_BOOL bModifier,
+                       FX_BOOL bShift,
+                       CPDF_FormField* pTarget) override {}
+  void OnField_Focus(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDF_FormField* pTarget,
+                     const CFX_WideString& Value) override {}
+  void OnField_Blur(FX_BOOL bModifier,
+                    FX_BOOL bShift,
+                    CPDF_FormField* pTarget,
+                    const CFX_WideString& Value) override {}
+  void OnField_Calculate(CPDF_FormField* pSource,
+                         CPDF_FormField* pTarget,
+                         CFX_WideString& Value,
+                         FX_BOOL& bRc) override {}
+  void OnField_Format(CPDF_FormField* pTarget,
+                      CFX_WideString& Value,
+                      FX_BOOL bWillCommit) override {}
+  void OnField_Keystroke(CFX_WideString& strChange,
+                         const CFX_WideString& strChangeEx,
+                         FX_BOOL KeyDown,
+                         FX_BOOL bModifier,
+                         int& nSelEnd,
+                         int& nSelStart,
+                         FX_BOOL bShift,
+                         CPDF_FormField* pTarget,
+                         CFX_WideString& Value,
+                         FX_BOOL bWillCommit,
+                         FX_BOOL bFieldFull,
+                         FX_BOOL& bRc) override {}
+  void OnField_Validate(CFX_WideString& strChange,
+                        const CFX_WideString& strChangeEx,
+                        FX_BOOL bKeyDown,
+                        FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDF_FormField* pTarget,
+                        CFX_WideString& Value,
+                        FX_BOOL& bRc) override {}
+  void OnScreen_Focus(FX_BOOL bModifier,
+                      FX_BOOL bShift,
+                      CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_Blur(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_Open(FX_BOOL bModifier,
+                     FX_BOOL bShift,
+                     CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_Close(FX_BOOL bModifier,
+                      FX_BOOL bShift,
+                      CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_MouseDown(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_MouseUp(FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_MouseEnter(FX_BOOL bModifier,
+                           FX_BOOL bShift,
+                           CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_MouseExit(FX_BOOL bModifier,
+                          FX_BOOL bShift,
+                          CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_InView(FX_BOOL bModifier,
+                       FX_BOOL bShift,
+                       CPDFSDK_Annot* pScreen) override {}
+  void OnScreen_OutView(FX_BOOL bModifier,
+                        FX_BOOL bShift,
+                        CPDFSDK_Annot* pScreen) override {}
+  void OnBookmark_MouseUp(CPDF_Bookmark* pBookMark) override {}
+  void OnLink_MouseUp(CPDFSDK_Document* pTarget) override {}
+  void OnMenu_Exec(CPDFSDK_Document* pTarget, const CFX_WideString&) override {}
+  void OnBatchExec(CPDFSDK_Document* pTarget) override {}
+  void OnConsole_Exec() override {}
+  void OnExternal_Exec() override {}
+  void EnableMessageBox(FX_BOOL bEnable) override {}
+};
+
+class CJS_RuntimeStub final : public IJS_Runtime {
+ public:
+  CJS_RuntimeStub() : m_pDoc(nullptr) {}
+  ~CJS_RuntimeStub() override {}
+
+  IJS_Context* NewContext() override {
+    if (!m_pContext)
+      m_pContext.reset(new CJS_ContextStub());
+    return GetCurrentContext();
+  }
+
+  IJS_Context* GetCurrentContext() override { return m_pContext.get(); }
+  void ReleaseContext(IJS_Context* pContext) override {}
+
+  void SetReaderDocument(CPDFSDK_Document* pReaderDoc) override {
+    m_pDoc = pReaderDoc;
+  }
+  CPDFSDK_Document* GetReaderDocument() override { return m_pDoc; }
+
+ protected:
+  CPDFSDK_Document* m_pDoc;
+  nonstd::unique_ptr<CJS_ContextStub> m_pContext;
+};
+
+// static
+void IJS_Runtime::Initialize(unsigned int slot, void* isolate) {
+}
+
+// static
+IJS_Runtime* IJS_Runtime::Create(CPDFDoc_Environment* pEnv) {
+  return new CJS_RuntimeStub;
+}