Change DumpProcessWithoutCrash to use load-time dynamic linking

chrome/app/chrome_main.cc

Index: chrome/app/chrome_main.cc
diff --git a/chrome/app/chrome_main.cc b/chrome/app/chrome_main.cc
index 54524a637582253179bed17a895b563160ad0d17..4936a3ce2be78febadd2fc98436ab628ca735faa 100644
--- a/chrome/app/chrome_main.cc
+++ b/chrome/app/chrome_main.cc
@@ -33,6 +33,7 @@
 #include "chrome/common/chrome_constants.h"
 #include "chrome/install_static/initialize_from_primary_module.h"
 #include "chrome/install_static/install_details.h"
+#include "chrome_elf/chrome_elf_main.h"
 
 #define DLLEXPORT __declspec(dllexport)
 
@@ -73,15 +74,7 @@ int ChromeMain(int argc, const char** argv) {
   params.instance = instance;
   params.sandbox_info = sandbox_info;
 
-  // SetDumpWithoutCrashingFunction must be passed the DumpProcess function
-  // from chrome_elf and not from the DLL in order for DumpWithoutCrashing to
-  // function correctly.
-  typedef void (__cdecl *DumpProcessFunction)();
-  DumpProcessFunction DumpProcess = reinterpret_cast<DumpProcessFunction>(
-      ::GetProcAddress(::GetModuleHandle(chrome::kChromeElfDllName),
-                       "DumpProcessWithoutCrash"));
-  CHECK(DumpProcess);
-  base::debug::SetDumpWithoutCrashingFunction(DumpProcess);
+  base::debug::SetDumpWithoutCrashingFunction(GetDumpWithoutCrashingFunction());

[scottmg, 2017/06/15 23:08:47]

Why does this have to be a function that returns a function, can't it just be a
function that we reference instead?

[Will Harris, 2017/06/15 23:37:24]

base can't call out of base, which is why we pass the function into base using
SetDumpWithoutCrashingFunction.

we have to set the crash function in the right copy of base, there's one linked
with each executable. This sets the crash function for chrome.exe which is why
it's in chromemain.

Hope that makes sense.

[scottmg, 2017/06/16 00:26:24]

But couldn't it just be 

  base::debug::SetDumpWithoutCrashingFunction(&DumpWithoutCrashingFunction);

?

[Will Harris, 2017/06/16 00:37:48]

maybe - but &DumpWithoutCrashingFunction would be in chrome_elf wouldn't it,
assuming the linker will still like this?

[Will Harris, 2017/06/21 14:31:26]

this is done, and verified that it calls down to the chrome_elf version for both
main exe and dll.

 
   // Verify that chrome_elf and this module (chrome.dll and chrome_child.dll)
   // have the same version.