The tricky part about logging to the console is that many of the errors are generated by invalid resources, from which we have no context. This means we don't know the instance to send the error message of.

Plumbing this through in a way that works proved much harder than I expected. I added log functions to the PpapiGlobals so that we can call it easily from all places. It can either go off an instance (like PPB_Console does) or a module, or nothing. In the module case, all consoles associated with all instances in the module get the log message, in the no context case, all consoles associated with any pepper plugin get the message.

In the IPC proxy, we know the module from whence the error came since there's a unique process for it. So proxied errors with no context when run out of process get translated into errors with PP_Module context. In the common case, there's only one instance for a module, so this works out nicely.

I added some logging ability to resources and added some errors to Graphics2D and URLLoader. We can add messages to more classes as the need arises. I added some advice on writing them to the chromium pepper page.

Review URL: https://chromiumcodereview.appspot.com/9160017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119853 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 251 insertions, 78 deletions

diff --git a/ppapi/proxy/host_dispatcher.cc b/ppapi/proxy/host_dispatcher.cc
index efd1f56..fc7686f 100644
--- a/ppapi/proxy/host_dispatcher.cc
+++ b/ppapi/proxy/host_dispatcher.cc
@@ -14,6 +14,7 @@
 #include "ppapi/proxy/interface_list.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_creation_proxy.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
 
 namespace ppapi {
 namespace proxy {
@@ -174,6 +175,14 @@ bool HostDispatcher::OnMessageReceived(const IPC::Message& msg) {
   BoolRestorer restorer(&allow_plugin_reentrancy_);
   allow_plugin_reentrancy_ = false;
 
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(HostDispatcher, msg)
+    IPC_MESSAGE_HANDLER(PpapiHostMsg_LogWithSource, OnHostMsgLogWithSource)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+
+  if (handled)
+    return true;
   return Dispatcher::OnMessageReceived(msg);
 }
 
@@ -215,6 +224,19 @@ void HostDispatcher::OnInvalidMessageReceived() {
   // received.
 }
 
+void HostDispatcher::OnHostMsgLogWithSource(PP_Instance instance,
+                                            int int_log_level,
+                                            const std::string& source,
+                                            const std::string& value) {
+  PP_LogLevel_Dev level = static_cast<PP_LogLevel_Dev>(int_log_level);
+  if (instance) {
+    PpapiGlobals::Get()->LogWithSource(instance, level, source, value);
+  } else {
+    PpapiGlobals::Get()->BroadcastLogWithSource(pp_module_, level,
+                                                source, value);
+  }
+}
+
 // ScopedModuleReference -------------------------------------------------------
 
 ScopedModuleReference::ScopedModuleReference(Dispatcher* dispatcher) {
diff --git a/ppapi/proxy/host_dispatcher.h b/ppapi/proxy/host_dispatcher.h
index 31de206..1bacdfa 100644
--- a/ppapi/proxy/host_dispatcher.h
+++ b/ppapi/proxy/host_dispatcher.h
@@ -85,6 +85,11 @@ class PPAPI_PROXY_EXPORT HostDispatcher : public Dispatcher {
   virtual void OnInvalidMessageReceived();
 
  private:
+  void OnHostMsgLogWithSource(PP_Instance instance,
+                              int int_log_level,
+                              const std::string& source,
+                              const std::string& value);
+
   PP_Module pp_module_;
 
   // Maps interface name to whether that interface is supported. If an interface
diff --git a/ppapi/proxy/plugin_dispatcher.cc b/ppapi/proxy/plugin_dispatcher.cc
index b036978..efe0803 100644
--- a/ppapi/proxy/plugin_dispatcher.cc
+++ b/ppapi/proxy/plugin_dispatcher.cc
@@ -40,6 +40,9 @@ namespace {
 typedef std::map<PP_Instance, PluginDispatcher*> InstanceToDispatcherMap;
 InstanceToDispatcherMap* g_instance_to_dispatcher = NULL;
 
+typedef std::set<PluginDispatcher*> DispatcherSet;
+DispatcherSet* g_live_dispatchers = NULL;
+
 }  // namespace
 
 InstanceData::InstanceData()
@@ -60,11 +63,21 @@ PluginDispatcher::PluginDispatcher(base::ProcessHandle remote_process_handle,
       received_preferences_(false),
       plugin_dispatcher_id_(0) {
   SetSerializationRules(new PluginVarSerializationRules);
+
+  if (!g_live_dispatchers)
+    g_live_dispatchers = new DispatcherSet;
+  g_live_dispatchers->insert(this);
 }
 
 PluginDispatcher::~PluginDispatcher() {
   if (plugin_delegate_)
     plugin_delegate_->Unregister(plugin_dispatcher_id_);
+
+  g_live_dispatchers->erase(this);
+  if (g_live_dispatchers->empty()) {
+    delete g_live_dispatchers;
+    g_live_dispatchers = NULL;
+  }
 }
 
 // static
@@ -88,6 +101,33 @@ const void* PluginDispatcher::GetBrowserInterface(const char* interface_name) {
   return InterfaceList::GetInstance()->GetInterfaceForPPB(interface_name);
 }
 
+// static
+void PluginDispatcher::LogWithSource(PP_Instance instance,
+                                     PP_LogLevel_Dev level,
+                                     const std::string& source,
+                                     const std::string& value) {
+  if (!g_live_dispatchers || !g_instance_to_dispatcher)
+    return;
+
+  if (instance) {
+    InstanceToDispatcherMap::iterator found =
+        g_instance_to_dispatcher->find(instance);
+    if (found != g_instance_to_dispatcher->end()) {
+      // Send just to this specific dispatcher.
+      found->second->Send(new PpapiHostMsg_LogWithSource(
+          instance, static_cast<int>(level), source, value));
+      return;
+    }
+  }
+
+  // Instance 0 or invalid, send to all dispatchers.
+  for (DispatcherSet::iterator i = g_live_dispatchers->begin();
+       i != g_live_dispatchers->end(); ++i) {
+    (*i)->Send(new PpapiHostMsg_LogWithSource(
+        instance, static_cast<int>(level), source, value));
+  }
+}
+
 const void* PluginDispatcher::GetPluginInterface(
     const std::string& interface_name) {
   InterfaceMap::iterator found = plugin_interfaces_.find(interface_name);
diff --git a/ppapi/proxy/plugin_dispatcher.h b/ppapi/proxy/plugin_dispatcher.h
index 947ab0a..55806b4 100644
--- a/ppapi/proxy/plugin_dispatcher.h
+++ b/ppapi/proxy/plugin_dispatcher.h
@@ -13,6 +13,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/process.h"
 #include "build/build_config.h"
+#include "ppapi/c/dev/ppb_console_dev.h"
 #include "ppapi/c/pp_rect.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/proxy/dispatcher.h"
@@ -80,6 +81,14 @@ class PPAPI_PROXY_EXPORT PluginDispatcher : public Dispatcher {
   // a browser interface.
   static const void* GetBrowserInterface(const char* interface_name);
 
+  // Logs the given log message to the given instance, or, if the instance is
+  // invalid, to all instances associated with all dispatchers. Used for
+  // global log messages.
+  static void LogWithSource(PP_Instance instance,
+                            PP_LogLevel_Dev level,
+                            const std::string& source,
+                            const std::string& value);
+
   const void* GetPluginInterface(const std::string& interface_name);
 
   // You must call this function before anything else. Returns true on success.
diff --git a/ppapi/proxy/plugin_globals.cc b/ppapi/proxy/plugin_globals.cc
index 360f221..5218dc4 100644
--- a/ppapi/proxy/plugin_globals.cc
+++ b/ppapi/proxy/plugin_globals.cc
@@ -5,6 +5,7 @@
 #include "ppapi/proxy/plugin_globals.h"
 
 #include "ppapi/proxy/plugin_dispatcher.h"
+#include "ppapi/thunk/enter.h"
 
 namespace ppapi {
 namespace proxy {
@@ -66,6 +67,24 @@ base::Lock* PluginGlobals::GetProxyLock() {
 #endif
 }
 
+void PluginGlobals::LogWithSource(PP_Instance instance,
+                                  PP_LogLevel_Dev level,
+                                  const std::string& source,
+                                  const std::string& value) {
+  const std::string& fixed_up_source = source.empty() ? plugin_name_ : source;
+  PluginDispatcher::LogWithSource(instance, level, fixed_up_source, value);
+}
+
+void PluginGlobals::BroadcastLogWithSource(PP_Module /* module */,
+                                           PP_LogLevel_Dev level,
+                                           const std::string& source,
+                                           const std::string& value) {
+  // Since we have only one module in a plugin process, broadcast is always
+  // the same as "send to everybody" which is what the dispatcher implements
+  // for the "instance = 0" case.
+  LogWithSource(0, level, source, value);
+}
+
 bool PluginGlobals::IsPluginGlobals() const {
   return true;
 }
diff --git a/ppapi/proxy/plugin_globals.h b/ppapi/proxy/plugin_globals.h
index 0b47616..1cf3661 100644
--- a/ppapi/proxy/plugin_globals.h
+++ b/ppapi/proxy/plugin_globals.h
@@ -41,6 +41,14 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
                                             ApiID id) OVERRIDE;
   virtual PP_Module GetModuleForInstance(PP_Instance instance) OVERRIDE;
   virtual base::Lock* GetProxyLock() OVERRIDE;
+  virtual void LogWithSource(PP_Instance instance,
+                             PP_LogLevel_Dev level,
+                             const std::string& source,
+                             const std::string& value) OVERRIDE;
+  virtual void BroadcastLogWithSource(PP_Module module,
+                                      PP_LogLevel_Dev level,
+                                      const std::string& source,
+                                      const std::string& value) OVERRIDE;
 
   // Getters for the plugin-specific versions.
   PluginResourceTracker* plugin_resource_tracker() {
@@ -58,6 +66,10 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
     plugin_proxy_delegate_ = d;
   }
 
+  // The embedder should call this function when the name of the plugin module
+  // is known. This will be used for error logging.
+  void set_plugin_name(const std::string& name) { plugin_name_ = name; }
+
  private:
   // PpapiGlobals overrides.
   virtual bool IsPluginGlobals() const OVERRIDE;
@@ -70,6 +82,10 @@ class PPAPI_PROXY_EXPORT PluginGlobals : public PpapiGlobals {
   scoped_refptr<CallbackTracker> callback_tracker_;
   base::Lock proxy_lock_;
 
+  // Name of the plugin used for error logging. This will be empty until
+  // SetPluginName is called.
+  std::string plugin_name_;
+
   DISALLOW_COPY_AND_ASSIGN(PluginGlobals);
 };
 
diff --git a/ppapi/proxy/ppapi_messages.h b/ppapi/proxy/ppapi_messages.h
index ef5ee81..6947f49 100644
--- a/ppapi/proxy/ppapi_messages.h
+++ b/ppapi/proxy/ppapi_messages.h
@@ -511,6 +511,13 @@ IPC_MESSAGE_ROUTED2(PpapiMsg_PPPVideoDecoder_NotifyError,
 IPC_MESSAGE_CONTROL1(PpapiHostMsg_ChannelCreated,
                      IPC::ChannelHandle /* handle */)
 
+// Logs the given message to the console of all instances.
+IPC_MESSAGE_CONTROL4(PpapiHostMsg_LogWithSource,
+                     PP_Instance /* instance */,
+                     int /* log_level */,
+                     std::string /* source */,
+                     std::string /* value */)
+
 // PPB_Audio.
 IPC_SYNC_MESSAGE_ROUTED3_1(PpapiHostMsg_PPBAudio_Create,
                            PP_Instance /* instance_id */,
@@ -909,15 +916,6 @@ IPC_SYNC_MESSAGE_ROUTED2_2(PpapiHostMsg_PPBInstance_ExecuteScript,
 IPC_SYNC_MESSAGE_ROUTED1_1(PpapiHostMsg_PPBInstance_GetDefaultCharSet,
                            PP_Instance /* instance */,
                            ppapi::proxy::SerializedVar /* result */)
-IPC_MESSAGE_ROUTED3(PpapiHostMsg_PPBInstance_Log,
-                    PP_Instance /* instance */,
-                    int /* log_level */,
-                    ppapi::proxy::SerializedVar /* value */)
-IPC_MESSAGE_ROUTED4(PpapiHostMsg_PPBInstance_LogWithSource,
-                    PP_Instance /* instance */,
-                    int /* log_level */,
-                    ppapi::proxy::SerializedVar /* source */,
-                    ppapi::proxy::SerializedVar /* value */)
 IPC_SYNC_MESSAGE_ROUTED2_1(PpapiHostMsg_PPBInstance_SetFullscreen,
                            PP_Instance /* instance */,
                            PP_Bool /* fullscreen */,
diff --git a/ppapi/proxy/ppb_graphics_2d_proxy.cc b/ppapi/proxy/ppb_graphics_2d_proxy.cc
index 0788361..b719a6b 100644
--- a/ppapi/proxy/ppb_graphics_2d_proxy.cc
+++ b/ppapi/proxy/ppb_graphics_2d_proxy.cc
@@ -91,8 +91,11 @@ void Graphics2D::PaintImageData(PP_Resource image_data,
                                 const PP_Rect* src_rect) {
   Resource* image_object =
       PpapiGlobals::Get()->GetResourceTracker()->GetResource(image_data);
-  if (!image_object || pp_instance() != image_object->pp_instance())
+  if (!image_object || pp_instance() != image_object->pp_instance()) {
+    Log(PP_LOGLEVEL_ERROR,
+        "PPB_Graphics2D.PaintImageData: Bad image resource.");
     return;
+  }
 
   PP_Rect dummy;
   memset(&dummy, 0, sizeof(PP_Rect));
@@ -113,8 +116,11 @@ void Graphics2D::Scroll(const PP_Rect* clip_rect,
 void Graphics2D::ReplaceContents(PP_Resource image_data) {
   Resource* image_object =
       PpapiGlobals::Get()->GetResourceTracker()->GetResource(image_data);
-  if (!image_object || pp_instance() != image_object->pp_instance())
+  if (!image_object || pp_instance() != image_object->pp_instance()) {
+    Log(PP_LOGLEVEL_ERROR,
+        "PPB_Graphics2D.PaintImageData: Bad image resource.");
     return;
+  }
 
   GetDispatcher()->Send(new PpapiHostMsg_PPBGraphics2D_ReplaceContents(
       kApiID, host_resource(), image_object->host_resource()));
diff --git a/ppapi/proxy/ppb_instance_proxy.cc b/ppapi/proxy/ppb_instance_proxy.cc
index 1a71966..62335c2 100644
--- a/ppapi/proxy/ppb_instance_proxy.cc
+++ b/ppapi/proxy/ppb_instance_proxy.cc
@@ -84,10 +84,6 @@ bool PPB_Instance_Proxy::OnMessageReceived(const IPC::Message& msg) {
                         OnHostMsgExecuteScript)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBInstance_GetDefaultCharSet,
                         OnHostMsgGetDefaultCharSet)
-    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBInstance_Log,
-                        OnHostMsgLog)
-    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBInstance_LogWithSource,
-                        OnHostMsgLogWithSource)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBInstance_PostMessage,
                         OnHostMsgPostMessage)
     IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBInstance_FlashSetFullscreen,
@@ -198,24 +194,6 @@ PP_Var PPB_Instance_Proxy::GetDefaultCharSet(PP_Instance instance) {
   return result.Return(dispatcher);
 }
 
-void PPB_Instance_Proxy::Log(PP_Instance instance,
-                             int log_level,
-                             PP_Var value) {
-  dispatcher()->Send(new PpapiHostMsg_PPBInstance_Log(
-      API_ID_PPB_INSTANCE, instance, static_cast<int>(log_level),
-      SerializedVarSendInput(dispatcher(), value)));
-}
-
-void PPB_Instance_Proxy::LogWithSource(PP_Instance instance,
-                                       int log_level,
-                                       PP_Var source,
-                                       PP_Var value) {
-  dispatcher()->Send(new PpapiHostMsg_PPBInstance_LogWithSource(
-      API_ID_PPB_INSTANCE, instance, static_cast<int>(log_level),
-      SerializedVarSendInput(dispatcher(), source),
-      SerializedVarSendInput(dispatcher(), value)));
-}
-
 void PPB_Instance_Proxy::NumberOfFindResultsChanged(PP_Instance instance,
                                                     int32_t total,
                                                     PP_Bool final_result) {
@@ -461,27 +439,6 @@ void PPB_Instance_Proxy::OnHostMsgGetDefaultCharSet(
     result.Return(dispatcher(), enter.functions()->GetDefaultCharSet(instance));
 }
 
-void PPB_Instance_Proxy::OnHostMsgLog(PP_Instance instance,
-                                      int log_level,
-                                      SerializedVarReceiveInput value) {
-  EnterInstanceNoLock enter(instance, false);
-  if (enter.succeeded())
-    enter.functions()->Log(instance, log_level, value.Get(dispatcher()));
-}
-
-void PPB_Instance_Proxy::OnHostMsgLogWithSource(
-    PP_Instance instance,
-    int log_level,
-    SerializedVarReceiveInput source,
-    SerializedVarReceiveInput value) {
-  EnterInstanceNoLock enter(instance, false);
-  if (enter.succeeded()) {
-    enter.functions()->LogWithSource(instance, log_level,
-                                     source.Get(dispatcher()),
-                                     value.Get(dispatcher()));
-  }
-}
-
 void PPB_Instance_Proxy::OnHostMsgSetFullscreen(PP_Instance instance,
                                                 PP_Bool fullscreen,
                                                 PP_Bool* result) {
diff --git a/ppapi/proxy/ppb_instance_proxy.h b/ppapi/proxy/ppb_instance_proxy.h
index 0ce2562..71107e4 100644
--- a/ppapi/proxy/ppb_instance_proxy.h
+++ b/ppapi/proxy/ppb_instance_proxy.h
@@ -29,8 +29,7 @@ class SerializedVarOutParam;
 class SerializedVarReturnValue;
 
 class PPB_Instance_Proxy : public InterfaceProxy,
-                           public PPB_Instance_Shared,
-                           public thunk::PPB_Instance_FunctionAPI {
+                           public PPB_Instance_Shared {
  public:
   PPB_Instance_Proxy(Dispatcher* dispatcher);
   virtual ~PPB_Instance_Proxy();
@@ -54,13 +53,6 @@ class PPB_Instance_Proxy : public InterfaceProxy,
                                PP_Var script,
                                PP_Var* exception) OVERRIDE;
   virtual PP_Var GetDefaultCharSet(PP_Instance instance) OVERRIDE;
-  virtual void Log(PP_Instance instance,
-                   int log_level,
-                   PP_Var value) OVERRIDE;
-  virtual void LogWithSource(PP_Instance instance,
-                             int log_level,
-                             PP_Var source,
-                             PP_Var value) OVERRIDE;
   virtual void NumberOfFindResultsChanged(PP_Instance instance,
                                           int32_t total,
                                           PP_Bool final_result) OVERRIDE;
@@ -122,13 +114,6 @@ class PPB_Instance_Proxy : public InterfaceProxy,
                               SerializedVarReturnValue result);
   void OnHostMsgGetDefaultCharSet(PP_Instance instance,
                                   SerializedVarReturnValue result);
-  void OnHostMsgLog(PP_Instance instance,
-                    int log_level,
-                    SerializedVarReceiveInput value);
-  void OnHostMsgLogWithSource(PP_Instance instance,
-                              int log_level,
-                              SerializedVarReceiveInput source,
-                              SerializedVarReceiveInput value);
   void OnHostMsgSetFullscreen(PP_Instance instance,
                               PP_Bool fullscreen,
                               PP_Bool* result);
diff --git a/ppapi/proxy/ppb_url_loader_proxy.cc b/ppapi/proxy/ppb_url_loader_proxy.cc
index de74318..c896050 100644
--- a/ppapi/proxy/ppb_url_loader_proxy.cc
+++ b/ppapi/proxy/ppb_url_loader_proxy.cc
@@ -179,8 +179,13 @@ PPB_URLLoader_API* URLLoader::AsPPB_URLLoader_API() {
 int32_t URLLoader::Open(PP_Resource request_id,
                         PP_CompletionCallback callback) {
   EnterResourceNoLock<thunk::PPB_URLRequestInfo_API> enter(request_id, true);
-  if (enter.failed())
+  if (enter.failed()) {
+    Log(PP_LOGLEVEL_ERROR, "PPB_URLLoader.Open: The URL you're requesting is "
+        " on a different security origin than your plugin. To request "
+        " cross-origin resources, see "
+        " PP_URLREQUESTPROPERTY_ALLOWCROSSORIGINREQUESTS.");
     return PP_ERROR_BADRESOURCE;
+  }
 
   if (TrackedCallback::IsPending(current_callback_))
     return PP_ERROR_INPROGRESS;
diff --git a/ppapi/shared_impl/ppapi_globals.h b/ppapi/shared_impl/ppapi_globals.h
index 737c3a2..d83e9c6 100644
--- a/ppapi/shared_impl/ppapi_globals.h
+++ b/ppapi/shared_impl/ppapi_globals.h
@@ -5,8 +5,11 @@
 #ifndef PPAPI_SHARED_IMPL_PPAPI_GLOBALS_H_
 #define PPAPI_SHARED_IMPL_PPAPI_GLOBALS_H_
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/threading/thread_local.h"  // For testing purposes only.
+#include "ppapi/c/dev/ppb_console_dev.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_module.h"
 #include "ppapi/shared_impl/api_id.h"
@@ -64,6 +67,26 @@ class PPAPI_SHARED_EXPORT PpapiGlobals {
       PP_Instance instance) = 0;
   virtual base::Lock* GetProxyLock() = 0;
 
+  // Logs the given string to the JS console. If "source" is empty, the name of
+  // the current module will be used, if it can be determined.
+  virtual void LogWithSource(PP_Instance instance,
+                             PP_LogLevel_Dev level,
+                             const std::string& source,
+                             const std::string& value) = 0;
+
+  // Like LogWithSource but broadcasts the log to all instances of the given
+  // module. The module may be 0 to specify that all consoles possibly
+  // associated with the calling code should be notified. This allows us to
+  // log errors for things like bad resource IDs where we may not have an
+  // associated instance.
+  //
+  // Note that in the plugin process, the module parameter is ignored since
+  // there is only one possible one.
+  virtual void BroadcastLogWithSource(PP_Module module,
+                                      PP_LogLevel_Dev level,
+                                      const std::string& source,
+                                      const std::string& value) = 0;
+
   // Returns the function object corresponding to the given ID, or NULL if
   // there isn't one.
   virtual FunctionGroupBase* GetFunctionAPI(PP_Instance inst, ApiID id) = 0;
diff --git a/ppapi/shared_impl/ppb_instance_shared.cc b/ppapi/shared_impl/ppb_instance_shared.cc
index a2416ce..7e931c3 100644
--- a/ppapi/shared_impl/ppb_instance_shared.cc
+++ b/ppapi/shared_impl/ppb_instance_shared.cc
@@ -4,14 +4,38 @@
 
 #include "ppapi/shared_impl/ppb_instance_shared.h"
 
+#include <string>
+
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_input_event.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/var.h"
 
 namespace ppapi {
 
 PPB_Instance_Shared::~PPB_Instance_Shared() {
 }
 
+void PPB_Instance_Shared::Log(PP_Instance instance,
+                              PP_LogLevel_Dev level,
+                              PP_Var value) {
+  LogWithSource(instance, level, PP_MakeUndefined(), value);
+}
+
+void PPB_Instance_Shared::LogWithSource(PP_Instance instance,
+                                        PP_LogLevel_Dev level,
+                                        PP_Var source,
+                                        PP_Var value) {
+  // The source defaults to empty if it's not a string. The PpapiGlobals
+  // implementation will convert the empty string to the module name if
+  // possible.
+  std::string source_str;
+  if (source.type == PP_VARTYPE_STRING)
+    source_str = Var::PPVarToLogString(source);
+  std::string value_str = Var::PPVarToLogString(value);
+  PpapiGlobals::Get()->LogWithSource(instance, level, source_str, value_str);
+}
+
 int32_t PPB_Instance_Shared::ValidateRequestInputEvents(
     bool is_filtering,
     uint32_t event_classes) {
diff --git a/ppapi/shared_impl/ppb_instance_shared.h b/ppapi/shared_impl/ppb_instance_shared.h
index 353a822..2842160 100644
--- a/ppapi/shared_impl/ppb_instance_shared.h
+++ b/ppapi/shared_impl/ppb_instance_shared.h
@@ -5,15 +5,27 @@
 #ifndef PPAPI_SHARED_IMPL_PPB_INSTANCE_SHARED_H_
 #define PPAPI_SHARED_IMPL_PPB_INSTANCE_SHARED_H_
 
+#include "base/compiler_specific.h"
 #include "ppapi/c/pp_stdint.h"
 #include "ppapi/shared_impl/ppapi_shared_export.h"
+#include "ppapi/thunk/ppb_instance_api.h"
 
 namespace ppapi {
 
-class PPAPI_SHARED_EXPORT PPB_Instance_Shared {
+class PPAPI_SHARED_EXPORT PPB_Instance_Shared
+    : NON_EXPORTED_BASE(public thunk::PPB_Instance_FunctionAPI) {
  public:
   virtual ~PPB_Instance_Shared();
 
+  // Implementation of some shared PPB_Instance_FunctionAPI functions.
+  virtual void Log(PP_Instance instance,
+                   PP_LogLevel_Dev log_level,
+                   PP_Var value) OVERRIDE;
+  virtual void LogWithSource(PP_Instance instance,
+                             PP_LogLevel_Dev log_level,
+                             PP_Var source,
+                             PP_Var value) OVERRIDE;
+
   // Error checks the given resquest to Request[Filtering]InputEvents. Returns
   // PP_OK if the given classes are all valid, PP_ERROR_NOTSUPPORTED if not.
   int32_t ValidateRequestInputEvents(bool is_filtering, uint32_t event_classes);
diff --git a/ppapi/shared_impl/resource.cc b/ppapi/shared_impl/resource.cc
index 4e1f2a8..35add15 100644
--- a/ppapi/shared_impl/resource.cc
+++ b/ppapi/shared_impl/resource.cc
@@ -45,6 +45,11 @@ void Resource::InstanceWasDeleted() {
   host_resource_ = HostResource();
 }
 
+void Resource::Log(PP_LogLevel_Dev level, const std::string& message) {
+  PpapiGlobals::Get()->LogWithSource(pp_instance(), level, std::string(),
+                                     message);
+}
+
 #define DEFINE_TYPE_GETTER(RESOURCE) \
   thunk::RESOURCE* Resource::As##RESOURCE() { return NULL; }
 FOR_ALL_PPAPI_RESOURCE_APIS(DEFINE_TYPE_GETTER)
diff --git a/ppapi/shared_impl/resource.h b/ppapi/shared_impl/resource.h
index 1c268b0..19775c3 100644
--- a/ppapi/shared_impl/resource.h
+++ b/ppapi/shared_impl/resource.h
@@ -7,10 +7,13 @@
 
 #include <stddef.h>  // For NULL.
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_resource.h"
+#include "ppapi/c/dev/ppb_console_dev.h"
 #include "ppapi/shared_impl/host_resource.h"
 
 // All resource types should be added here. This implements our hand-rolled
@@ -125,6 +128,10 @@ class PPAPI_SHARED_EXPORT Resource : public base::RefCounted<Resource> {
   // Template-based dynamic casting. See specializations below.
   template <typename T> T* GetAs() { return NULL; }
 
+ protected:
+  // Logs a message to the console from this resource.
+  void Log(PP_LogLevel_Dev level, const std::string& message);
+
  private:
   // See the getters above.
   PP_Resource pp_resource_;
diff --git a/ppapi/shared_impl/test_globals.cc b/ppapi/shared_impl/test_globals.cc
index f661998..102dc11 100644
--- a/ppapi/shared_impl/test_globals.cc
+++ b/ppapi/shared_impl/test_globals.cc
@@ -44,4 +44,16 @@ base::Lock* TestGlobals::GetProxyLock() {
   return NULL;
 }
 
+void TestGlobals::LogWithSource(PP_Instance instance,
+                                PP_LogLevel_Dev level,
+                                const std::string& source,
+                                const std::string& value) {
+}
+
+void TestGlobals::BroadcastLogWithSource(PP_Module module,
+                                         PP_LogLevel_Dev level,
+                                         const std::string& source,
+                                         const std::string& value) {
+}
+
 }  // namespace ppapi
diff --git a/ppapi/shared_impl/test_globals.h b/ppapi/shared_impl/test_globals.h
index 9af6664..ae6f4b2 100644
--- a/ppapi/shared_impl/test_globals.h
+++ b/ppapi/shared_impl/test_globals.h
@@ -39,6 +39,14 @@ class TestGlobals : public PpapiGlobals {
                                             ApiID id) OVERRIDE;
   virtual PP_Module GetModuleForInstance(PP_Instance instance) OVERRIDE;
   virtual base::Lock* GetProxyLock() OVERRIDE;
+  virtual void LogWithSource(PP_Instance instance,
+                             PP_LogLevel_Dev level,
+                             const std::string& source,
+                             const std::string& value) OVERRIDE;
+  virtual void BroadcastLogWithSource(PP_Module module,
+                                      PP_LogLevel_Dev level,
+                                      const std::string& source,
+                                      const std::string& value) OVERRIDE;
 
  private:
   ResourceTracker resource_tracker_;
diff --git a/ppapi/thunk/enter.cc b/ppapi/thunk/enter.cc
index 42f4a0e..43e80fe 100644
--- a/ppapi/thunk/enter.cc
+++ b/ppapi/thunk/enter.cc
@@ -7,7 +7,9 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/stringprintf.h"
 #include "ppapi/c/pp_errors.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
@@ -74,15 +76,32 @@ Resource* EnterBase::GetResource(PP_Resource resource) const {
   return PpapiGlobals::Get()->GetResourceTracker()->GetResource(resource);
 }
 
-void EnterBase::SetStateForResourceError(PP_Resource /* pp_resource */,
-                                         Resource* /* resource_base */,
+void EnterBase::SetStateForResourceError(PP_Resource pp_resource,
+                                         Resource* resource_base,
                                          void* object,
-                                         bool /* report_error */) {
+                                         bool report_error) {
   if (object)
     return;  // Everything worked.
 
   retval_ = PP_ERROR_BADRESOURCE;
-  // TODO(brettw) log the error.
+
+  // We choose to silently ignore the error when the pp_resource is null
+  // because this is a pretty common case and we don't want to have lots
+  // of errors in the log. This should be an obvious case to debug.
+  if (report_error && pp_resource) {
+    std::string message;
+    if (resource_base) {
+      message = base::StringPrintf(
+          "0x%X is not the correct type for this function.",
+          pp_resource);
+    } else {
+      message = base::StringPrintf(
+          "0x%X is not a valid resource ID.",
+          pp_resource);
+    }
+    PpapiGlobals::Get()->BroadcastLogWithSource(0, PP_LOGLEVEL_ERROR,
+                                                std::string(), message);
+  }
 }
 
 }  // namespace subtle
diff --git a/ppapi/thunk/ppb_instance_api.h b/ppapi/thunk/ppb_instance_api.h
index 013f61b..6d0339a 100644
--- a/ppapi/thunk/ppb_instance_api.h
+++ b/ppapi/thunk/ppb_instance_api.h
@@ -5,6 +5,7 @@
 #ifndef PPAPI_THUNK_INSTANCE_API_H_
 #define PPAPI_THUNK_INSTANCE_API_H_
 
+#include "ppapi/c/dev/ppb_console_dev.h"
 #include "ppapi/c/dev/ppb_gamepad_dev.h"
 #include "ppapi/c/dev/ppb_url_util_dev.h"
 #include "ppapi/c/pp_completion_callback.h"
@@ -47,10 +48,10 @@ class PPB_Instance_FunctionAPI {
 
   // Console.
   virtual void Log(PP_Instance instance,
-                   int log_level,
+                   PP_LogLevel_Dev log_level,
                    PP_Var value) = 0;
   virtual void LogWithSource(PP_Instance instance,
-                             int log_level,
+                             PP_LogLevel_Dev log_level,
                              PP_Var source,
                              PP_Var value) = 0;