Ensure that the DirectWrite font cache works in Chrome canary on Windows 8+ with AppContainer prote…

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 69d34d542ad96490de6720db63ee075e3b229c24..aa641535602a062bf6427dab39500cb8e8823afe 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -175,11 +175,14 @@
 #endif
 
 #if defined(OS_WIN)
+#include "base/memory/shared_memory.h"
 #include "base/win/scoped_com_initializer.h"
 #include "base/win/windows_version.h"
 #include "content/common/font_cache_dispatcher_win.h"
 #include "content/common/sandbox_win.h"
+#include "content/public/common/dwrite_font_platform_win.h"
 #include "sandbox/win/src/sandbox_policy.h"
+#include "ui/gfx/win/direct_write.h"
 #include "ui/gfx/win/dpi.h"
 #endif
 
@@ -329,7 +332,9 @@ class RendererSandboxedProcessLauncherDelegate
   explicit RendererSandboxedProcessLauncherDelegate(IPC::ChannelProxy* channel)
 #if defined(OS_POSIX)
       : ipc_fd_(channel->TakeClientFileDescriptor())
-#endif  // OS_POSIX
+#elif defined(OS_WIN)
+      : direct_write_font_cache_section_(NULL)
+#endif  // OS_WIN
   {}
 
   ~RendererSandboxedProcessLauncherDelegate() override {}
@@ -356,9 +361,18 @@ class RendererSandboxedProcessLauncherDelegate
       }
     }
 
+    // If we have a valid DirectWrite font cache section then add its handle to
+    // the list of handles being shared with the renderer process.
+    if (direct_write_font_cache_section_)
+      policy->AddHandleToShare(direct_write_font_cache_section_);
+
     GetContentClient()->browser()->PreSpawnRenderer(policy, success);
   }
 
+  void set_direct_write_font_cache_handle(
+      base::SharedMemoryHandle direct_write_font_cache_section) {
+    direct_write_font_cache_section_ = direct_write_font_cache_section;

[Shrikant Kelkar, 2015/05/05 20:43:16]

Scope/DuplicateHandle?

[ananta, 2015/05/07 22:00:47]

This code is no longer needed. Based on a discussion with cpu, we decided to
move this code to content sandbox

+  }
 #elif defined(OS_POSIX)
   bool ShouldUseZygote() override {
     const base::CommandLine& browser_command_line =
@@ -374,6 +388,10 @@ class RendererSandboxedProcessLauncherDelegate
 #if defined(OS_POSIX)
   base::ScopedFD ipc_fd_;
 #endif  // OS_POSIX
+
+#if defined(OS_WIN)
+  base::SharedMemoryHandle direct_write_font_cache_section_;

[Shrikant Kelkar, 2015/05/05 20:43:15]

Scope? Who is the owner?

[ananta, 2015/05/07 22:00:48]

Reworked the patch to move the handle sharing and passing the duplicated handle
via the command line code to content sandbox

+#endif
 };
 
 const char kSessionStorageHolderKey[] = "kSessionStorageHolderKey";
@@ -665,6 +683,24 @@ bool RenderProcessHostImpl::Init() {
     g_in_process_thread = in_process_renderer_->message_loop();
 
   } else {
+    RendererSandboxedProcessLauncherDelegate* sandbox_delegate =
+        new RendererSandboxedProcessLauncherDelegate(channel_.get());
+#if defined(OS_WIN)
+    // If DirectWrite is enabled for font rendering then open the font cache
+    // section and pass the handle to the renderer process. This is needed
+    // because renderer processes on Windows 8+ may be running in an
+    // AppContainer sandbox and hence their kernel object namespace may be
+    // partitioned.
+    if (!run_renderer_in_process() && gfx::win::ShouldUseDirectWrite()) {
+        std::string name(content::kFontCacheSharedSectionName);
+        name.append(base::UintToString(base::GetCurrentProcId()));
+        direct_write_font_cache_section_.set_inheritable(true);
+        if (direct_write_font_cache_section_.Open(name, true)) {
+          sandbox_delegate->set_direct_write_font_cache_handle(
+              direct_write_font_cache_section_.handle());
+        }
+    }
+#endif
     // Build command line for renderer.  We call AppendRendererCommandLine()
     // first so the process type argument will appear first.
     base::CommandLine* cmd_line = new base::CommandLine(renderer_path);
@@ -677,7 +713,7 @@ bool RenderProcessHostImpl::Init() {
     // As long as there's no renderer prefix, we can use the zygote process
     // at this stage.
     child_process_launcher_.reset(new ChildProcessLauncher(
-        new RendererSandboxedProcessLauncherDelegate(channel_.get()),
+        sandbox_delegate,
         cmd_line,
         GetID(),
         this));
@@ -1198,9 +1234,12 @@ void RenderProcessHostImpl::AppendRendererCommandLine(
 #if defined(OS_WIN)
   command_line->AppendSwitchASCII(switches::kDeviceScaleFactor,
                                   base::DoubleToString(gfx::GetDPIScale()));
-  command_line->AppendSwitchASCII(
-      switches::kFontCacheSharedMemSuffix,
-      base::UintToString(base::GetCurrentProcId()));
+  if (direct_write_font_cache_section_.handle()) {
+    command_line->AppendSwitchASCII(
+        switches::kFontCacheSharedHandle,
+        base::UintToString(reinterpret_cast<unsigned int>(
+            direct_write_font_cache_section_.handle())));
+  }
 #endif
 
   AppendCompositorCommandLineFlags(command_line);