Added SkImageFilter serialization

content/common/cc_messages.cc

Index: content/common/cc_messages.cc
diff --git a/content/common/cc_messages.cc b/content/common/cc_messages.cc
index 9065a946ad3bc5ff857e30610170e469a4998575..42ce0f6ff8f26e44588f4058948de867c5c7b635 100644
--- a/content/common/cc_messages.cc
+++ b/content/common/cc_messages.cc
@@ -4,9 +4,13 @@
 
 #include "content/common/cc_messages.h"
 
+#include "base/command_line.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/filter_operations.h"
 #include "content/public/common/common_param_traits.h"
+#include "content/public/common/content_switches.h"
+#include "third_party/skia/src/core/SkOrderedReadBuffer.h"
+#include "third_party/skia/src/core/SkOrderedWriteBuffer.h"
 #include "ui/gfx/transform.h"
 
 namespace IPC {
@@ -185,6 +189,49 @@ void ParamTraits<cc::FilterOperations>::Log(
   l->append(")");
 }
 
+void ParamTraits<skia::RefPtr<SkImageFilter> >::Write(
+    Message* m, const param_type& p) {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  if (!command_line.HasSwitch(switches::kAllowFiltersOverIPC))
+    return;

[piman, 2013/08/01 19:53:22]

As it is, this relies on the flag being identical on both sides of the IPC. It's
probably true in this case, but there's always crazy reasons why they may not
be. If they aren't, then the entire IPC gets confused and we'll fail badly.

Could we instead, make the writer side write empty filter if the flag isn't set,
and the reader side always read the data, but discard it (before parsing) if the
flag isn't set?

That way we fall back sanely (no filter) if either side doesn't have the flag.

[sugoi1, 2013/08/01 20:23:28]

Done.

+  SkImageFilter* filter = p.get();
+  if (filter) {
+    SkOrderedWriteBuffer buffer(1024);
+    buffer.setFlags(SkOrderedWriteBuffer::kCrossProcess_Flag);
+    buffer.writeFlattenable(filter);
+    buffer.writeToMemory(m->BeginWriteData(buffer.bytesWritten()));
+  } else {
+    m->WriteData(0, 0);
+  }
+}
+
+bool ParamTraits<skia::RefPtr<SkImageFilter> >::Read(
+    const Message* m, PickleIterator* iter, param_type* r) {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  if (!command_line.HasSwitch(switches::kAllowFiltersOverIPC)) {
+    r->clear();
+    return true;
+  }
+  const char* data = 0;
+  int length = 0;
+  if (!m->ReadData(iter, &data, &length))
+    return false;
+  if (length > 0) {
+    SkOrderedReadBuffer buffer(data, length);
+    *r = skia::AdoptRef(buffer.readFlattenableT<SkImageFilter>());
+  } else {
+    r->clear();
+  }
+  return true;
+}
+
+void ParamTraits<skia::RefPtr<SkImageFilter> >::Log(
+    const param_type& p, std::string* l) {
+  l->append("(");
+  LogParam(p.get() ? p->countInputs() : 0, l);
+  l->append(")");
+}
+
 void ParamTraits<gfx::Transform>::Write(
     Message* m, const param_type& p) {
   WriteParam(m, p.matrix().getDouble(0, 0));