Moved the following IPC messages used by the chrome NPAPI plugin installer out of content

chrome/default_plugin/plugin_main.cc

Index: chrome/default_plugin/plugin_main.cc
===================================================================
--- chrome/default_plugin/plugin_main.cc	(revision 98657)
+++ chrome/default_plugin/plugin_main.cc	(working copy)
@@ -3,8 +3,10 @@
 // found in the LICENSE file.
 
 #include "chrome/default_plugin/plugin_main.h"
+#include "content/common/content_constants.h"
 
 #include "base/logging.h"
+#include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "chrome/default_plugin/plugin_impl.h"
 #include "webkit/glue/webkit_glue.h"
@@ -326,4 +328,30 @@
   return plugin_impl->NPP_HandleEvent(event);
 }
 
+
+// PluginInstallerBase member definitions.
+
+PluginInstallerBase::PluginInstallerBase()
+    : renderer_process_id_(0),
+      render_view_id_(0) {
+}
+
+PluginInstallerBase::~PluginInstallerBase() {
+}
+
+bool PluginInstallerBase::Initialize(void* module_handle, NPP instance,
+                                     NPMIMEType mime_type, int16 argc,
+                                     char* argn[], char* argv[]) {
+  for (int16_t index = 0; index < argc; ++index) {
+    if (!base::strncasecmp(argn[index], content::kPluginRenderProcessId,
+                           strlen(argn[index]))) {
+      base::StringToInt(argv[index], &renderer_process_id_);
+    } else if (!base::strncasecmp(argn[index], content::kPluginRenderViewId,
+                                  strlen(argn[index]))) {
+      base::StringToInt(argv[index], &render_view_id_);
+    }
+  }
+  return true;
+}
+
 }   // default_plugin