PPAPI: Make CallWhileUnlocked more permissive.

Prior to this patch, CallWhileUnlocked required its parameters' types to
be perfect matches to the types in the function pointer it's meant to
invoke. This is counter to programmers' usual expectations for function
calls, since the compiler will usually do safe casts like add const or
promoting integral types. This just adds template params to CallWhileUnlocked
so that any call with the appropriate number of parameters will be a template
match. The compiler will still decide if there is a valid implicit conversion,
so this is still safe in the sense that mismatched params still won't
compile.

BUG=160925

Review URL: https://codereview.chromium.org/552423003

Cr-Commit-Position: refs/heads/master@{#294405}

3 files changed, 9 insertions, 12 deletions

diff --git a/ppapi/proxy/ppp_content_decryptor_private_proxy.cc b/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
index 9d9afcc..e956d12 100644
--- a/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
+++ b/ppapi/proxy/ppp_content_decryptor_private_proxy.cc
@@ -688,7 +688,7 @@ void PPP_ContentDecryptor_Private_Proxy::OnMsgDecrypt(
     CallWhileUnlocked(ppp_decryptor_impl_->Decrypt,
                       instance,
                       plugin_resource.get(),
-                      const_cast<const PP_EncryptedBlockInfo*>(&block_info));
+                      &block_info);
   }
 }
 
@@ -713,7 +713,7 @@ void PPP_ContentDecryptor_Private_Proxy::OnMsgInitializeAudioDecoder(
     CallWhileUnlocked(
         ppp_decryptor_impl_->InitializeAudioDecoder,
         instance,
-        const_cast<const PP_AudioDecoderConfig*>(&decoder_config),
+        &decoder_config,
         plugin_resource.get());
   }
 }
@@ -739,7 +739,7 @@ void PPP_ContentDecryptor_Private_Proxy::OnMsgInitializeVideoDecoder(
     CallWhileUnlocked(
         ppp_decryptor_impl_->InitializeVideoDecoder,
         instance,
-        const_cast<const PP_VideoDecoderConfig*>(&decoder_config),
+        &decoder_config,
         plugin_resource.get());
   }
 }
@@ -793,7 +793,7 @@ void PPP_ContentDecryptor_Private_Proxy::OnMsgDecryptAndDecode(
         instance,
         decoder_type,
         plugin_resource.get(),
-        const_cast<const PP_EncryptedBlockInfo*>(&block_info));
+        &block_info);
   }
 }
 
diff --git a/ppapi/proxy/ppp_printing_proxy.cc b/ppapi/proxy/ppp_printing_proxy.cc
index 9d58c78..7b2ae55 100644
--- a/ppapi/proxy/ppp_printing_proxy.cc
+++ b/ppapi/proxy/ppp_printing_proxy.cc
@@ -167,11 +167,8 @@ void PPP_Printing_Proxy::OnPluginMsgBegin(PP_Instance instance,
     return;
   memcpy(&settings, &settings_string[0], sizeof(settings));
 
-  if (ppp_printing_impl_) {
-    *result = CallWhileUnlocked(ppp_printing_impl_->Begin,
-        instance,
-        const_cast<const PP_PrintSettings_Dev*>(&settings));
-  }
+  if (ppp_printing_impl_)
+    *result = CallWhileUnlocked(ppp_printing_impl_->Begin, instance, &settings);
 }
 
 void PPP_Printing_Proxy::OnPluginMsgPrintPages(
@@ -183,7 +180,7 @@ void PPP_Printing_Proxy::OnPluginMsgPrintPages(
 
   PP_Resource plugin_resource = CallWhileUnlocked(
       ppp_printing_impl_->PrintPages,
-      instance, &pages[0], static_cast<uint32_t>(pages.size()));
+      instance, &pages[0], pages.size());
   ResourceTracker* resource_tracker = PpapiGlobals::Get()->GetResourceTracker();
   Resource* resource_object = resource_tracker->GetResource(plugin_resource);
   if (!resource_object)
diff --git a/ppapi/proxy/video_capture_resource.cc b/ppapi/proxy/video_capture_resource.cc
index 8931b8f..5c95ed8 100644
--- a/ppapi/proxy/video_capture_resource.cc
+++ b/ppapi/proxy/video_capture_resource.cc
@@ -166,8 +166,8 @@ void VideoCaptureResource::OnPluginMsgOnDeviceInfo(
                     pp_instance(),
                     pp_resource(),
                     &info,
-                    static_cast<uint32_t>(buffers.size()),
-                    const_cast<const PP_Resource*>(resources.get()));
+                    buffers.size(),
+                    resources.get());
 
   for (size_t i = 0; i < buffers.size(); ++i)
     tracker->ReleaseResource(resources[i]);