Initialize V8 in PDFium from external files (plugin process only)

chrome/plugin/chrome_content_plugin_client.cc

Index: chrome/plugin/chrome_content_plugin_client.cc
diff --git a/chrome/plugin/chrome_content_plugin_client.cc b/chrome/plugin/chrome_content_plugin_client.cc
index 1abe0a3fd905db8aa19a7ab4f259f8f2c64dd706..87c20d03fc1f5f67b86ab77985c6db1e732137fd 100644
--- a/chrome/plugin/chrome_content_plugin_client.cc
+++ b/chrome/plugin/chrome_content_plugin_client.cc
@@ -17,9 +17,17 @@
 #endif
 #endif
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "gin/public/isolate_holder.h"
+#endif
+
 namespace chrome {
 
 void ChromeContentPluginClient::PreSandboxInitialization() {
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA

[raymes, 2014/11/11 03:26:39]

Should we just bury this #ifdef in gin as well or are there times when 
gin::IsolateHolder::LoadV8Snapshot(); needs to be called regardless of the
#ifdef?

[baixo1, 2014/11/11 10:56:11]

+jochen@

LoadV8Snapshot is currently only visible if V8_USE_EXTERNAL_STARTUP_DATA is
defined. When called, it'll try do map the files right away and return a bool
indicating success/failure.

I could expose this function even when V8_USE_EXTERNAL_STARTUP_DATA is *not*
defined as well and make it return "success" in such case (not using external
V8). Are you ok with this, Jochen?

[raymes, 2014/11/11 23:02:22]

Feel free to do this in a followup CL if it requires more complicated changes :)

+  gin::IsolateHolder::LoadV8Snapshot();

[raymes, 2014/11/11 03:26:39]

I suggest getting jschuh@ or cpu@ to review this part of the change, just to
make sure they are ok with adding this in before the sandbox initialization.

[baixo1, 2014/11/11 10:56:11]

+jschuh@ : could you take a look at this, please?

[jschuh, 2014/11/13 00:13:26]

When would this get enabled? I.e. is the V8_USE_EXTERNAL_STARTUP_DATA flag
enabled in stable builds of Chrome that we ship, or is this used in some other
context? 

+#endif
+
 #if defined(ENABLE_REMOTING)
 
   // Load crypto libraries for the Chromoting client plugin.