Convert visitedlink to use mojo.

components/visitedlink/renderer/visitedlink_slave.cc

Index: components/visitedlink/renderer/visitedlink_slave.cc
diff --git a/components/visitedlink/renderer/visitedlink_slave.cc b/components/visitedlink/renderer/visitedlink_slave.cc
index c159aba925749606665b4e7ba17a3d789d381073..2abe1a44d435d80ce5e779b1b8d7e153a71ab34c 100644
--- a/components/visitedlink/renderer/visitedlink_slave.cc
+++ b/components/visitedlink/renderer/visitedlink_slave.cc
@@ -8,86 +8,72 @@
 #include <stdint.h>
 
 #include "base/logging.h"
-#include "base/memory/shared_memory.h"
-#include "components/visitedlink/common/visitedlink_messages.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
 using blink::WebView;
 
 namespace visitedlink {
 
-VisitedLinkSlave::VisitedLinkSlave() : shared_memory_(NULL) {}
+VisitedLinkSlave::VisitedLinkSlave() : binding_(this) {}
 
 VisitedLinkSlave::~VisitedLinkSlave() {
   FreeTable();
 }
 
-bool VisitedLinkSlave::OnControlMessageReceived(const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(VisitedLinkSlave, message)
-    IPC_MESSAGE_HANDLER(ChromeViewMsg_VisitedLink_NewTable,
-                        OnUpdateVisitedLinks)
-    IPC_MESSAGE_HANDLER(ChromeViewMsg_VisitedLink_Add, OnAddVisitedLinks)
-    IPC_MESSAGE_HANDLER(ChromeViewMsg_VisitedLink_Reset, OnResetVisitedLinks)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
+void VisitedLinkSlave::Bind(mojom::VisitedLinkNotificationSinkRequest request) {
+  binding_.Bind(std::move(request));
 }
 
 // This function's job is to initialize the table with the given
 // shared memory handle. This memory is mapped into the process.
-void VisitedLinkSlave::OnUpdateVisitedLinks(base::SharedMemoryHandle table) {
-  DCHECK(base::SharedMemory::IsHandleValid(table)) << "Bad table handle";
+void VisitedLinkSlave::UpdateVisitedLinks(
+    mojo::ScopedSharedBufferHandle table) {
+  DCHECK(table.is_valid()) << "Bad table handle";
   // since this function may be called again to change the table, we may need
   // to free old objects
   FreeTable();
-  DCHECK(shared_memory_ == NULL && hash_table_ == NULL);
-
-  // create the shared memory object
-  shared_memory_ = new base::SharedMemory(table, true);
-  if (!shared_memory_)
-    return;
+  DCHECK(hash_table_ == NULL);
+
+  int32_t table_len = 0;
+  {
+    // map the header into our process so we can see how long the rest is,

[brettw, 2016/09/15 22:33:08]

Check that the new comments you added (also below) follow the guide of complete
sentences (looks like the old ones are wrong (probably my bad), but at least the
new ones can be improved).

[Sam McNally, 2016/09/19 00:28:19]

Done.

+    // and set the salt
+    mojo::ScopedSharedBufferMapping header_memory =
+        table->Map(sizeof(SharedHeader));
+    if (!header_memory)
+      return;
+
+    SharedHeader* header = static_cast<SharedHeader*>(header_memory.get());
+    table_len = header->length;
+    memcpy(salt_, header->salt, sizeof(salt_));
+  }
 
-  // map the header into our process so we can see how long the rest is,
-  // and set the salt
-  if (!shared_memory_->Map(sizeof(SharedHeader)))
-    return;
-  SharedHeader* header =
-    static_cast<SharedHeader*>(shared_memory_->memory());
-  DCHECK(header);
-  int32_t table_len = header->length;
-  memcpy(salt_, header->salt, sizeof(salt_));
-  shared_memory_->Unmap();
-
-  // now do the whole table because we know the length
-  if (!shared_memory_->Map(sizeof(SharedHeader) +
-                          table_len * sizeof(Fingerprint))) {
-    shared_memory_->Close();
+  // now do the table contents because we know the length
+  table_mapping_ =
+      table->MapAtOffset(table_len * sizeof(Fingerprint), sizeof(SharedHeader));
+  if (!table_mapping_)
     return;
-  }
 
   // commit the data
-  DCHECK(shared_memory_->memory());
-  hash_table_ = reinterpret_cast<Fingerprint*>(
-      static_cast<char*>(shared_memory_->memory()) + sizeof(SharedHeader));
+  hash_table_ = reinterpret_cast<Fingerprint*>(table_mapping_.get());
   table_length_ = table_len;
 }
 
-void VisitedLinkSlave::OnAddVisitedLinks(
-    const VisitedLinkSlave::Fingerprints& fingerprints) {
+void VisitedLinkSlave::AddVisitedLinks(
+    const std::vector<VisitedLinkSlave::Fingerprint>& fingerprints) {
   for (size_t i = 0; i < fingerprints.size(); ++i)
     WebView::updateVisitedLinkState(fingerprints[i]);
 }
 
-void VisitedLinkSlave::OnResetVisitedLinks(bool invalidate_hashes) {
+void VisitedLinkSlave::ResetVisitedLinks(bool invalidate_hashes) {
   WebView::resetVisitedLinkState(invalidate_hashes);
 }
 
 void VisitedLinkSlave::FreeTable() {
-  if (shared_memory_) {
-    delete shared_memory_;
-    shared_memory_ = NULL;
-  }
+  if (!hash_table_)
+    return;
+
+  table_mapping_.reset();
   hash_table_ = NULL;
   table_length_ = 0;
 }