Modify SetImageData to add additional items along with image data to save on clipboard.

extensions/browser/api/clipboard/clipboard_api.cc

Index: extensions/browser/api/clipboard/clipboard_api.cc
diff --git a/extensions/browser/api/clipboard/clipboard_api.cc b/extensions/browser/api/clipboard/clipboard_api.cc
index ef7373b821cc50d80cd1cfa1222657623846b78b..7f323d6851f869ca8d8d66f5038558bf066bc258 100644
--- a/extensions/browser/api/clipboard/clipboard_api.cc
+++ b/extensions/browser/api/clipboard/clipboard_api.cc
@@ -8,6 +8,7 @@
 
 #include "base/lazy_instance.h"
 #include "base/memory/ptr_util.h"
+#include "base/strings/string_util.h"
 #include "base/values.h"
 #include "extensions/browser/api/extensions_api_client.h"
 #include "extensions/browser/event_router.h"
@@ -17,6 +18,9 @@ namespace extensions {
 
 namespace clipboard = api::clipboard;
 
+const char kTextPlain[] = "text/plain";
+const char kTextHtml[] = "text/html";
+
 static base::LazyInstance<
     BrowserContextKeyedAPIFactory<ClipboardAPI>>::DestructorAtExit g_factory =
     LAZY_INSTANCE_INITIALIZER;
@@ -54,8 +58,13 @@ ExtensionFunction::ResponseAction ClipboardSetImageDataFunction::Run() {
   std::unique_ptr<clipboard::SetImageData::Params> params(
       clipboard::SetImageData::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params);
+
+  if (!IsAdditionalItemsParamValid(params->additional_items)) {
+    return RespondNow(Error("Unsupported additional_items parameter data."));
+  }
+
   ExtensionsAPIClient::Get()->SaveImageDataToClipboard(
-      params->image_data, params->type,
+      params->image_data, params->type, params->additional_items,
       base::Bind(&ClipboardSetImageDataFunction::OnSaveImageDataSuccess, this),
       base::Bind(&ClipboardSetImageDataFunction::OnSaveImageDataError, this));
   return RespondLater();
@@ -70,4 +79,39 @@ void ClipboardSetImageDataFunction::OnSaveImageDataError(
   Respond(Error(error));
 }
 
+bool ClipboardSetImageDataFunction::IsAdditionalItemsParamValid(
+    const AdditionalDataItemList& items) {
+  // It is possible for user to embed the base64 encoded image data in
+  // the addtional data item. We allow maxumum 4kx4k pixels for the orignal
+  // image size. Each pixel costs 4 byes, and base64 encoding ouput bytes
+  // to input bytes ration is 4:3. We also add an extra 2k for other data
+  // such as url, etc.
+  const size_t max_item_data_bytes =
+      std::ceil(4 * 1024 * 4 * 1024 * 4 / 3) * 4 + 2048;

[dcheng, 2017/04/27 15:42:09]

This is currently a runtime calculation, but it should just be calculated out.

FWIW, I think it'd be easier to just pick an arbitrary byte limit and just use
it rather than trying to say we'll allow images up to a certain size. In fact,
Chrome probably won't even load a data URL longer than 2 MB...

[jennyz, 2017/05/16 18:22:03]

Done.

+
+  if (items.size() > 2)
+    return false;

[dcheng, 2017/04/27 15:42:09]

I would just omit this, this will get caught by the for loop. No need to handle
this case separately.

[jennyz, 2017/05/16 18:22:03]

Done.

+  bool has_text_plain = false;
+  bool has_text_html = false;
+  for (const clipboard::AdditionalDataItem& item : items) {
+    std::string type = base::ToLowerASCII(item.type);
+    if (type != kTextPlain && type != kTextHtml)
+      return false;
+    if (type == kTextPlain) {
+      if (has_text_plain)
+        return false;
+      has_text_plain = true;
+    }
+    if (type == kTextHtml) {
+      if (has_text_html)
+        return false;
+      has_text_html = true;
+    }
+    // Check maximum length of the string data.
+    if (item.data.length() > max_item_data_bytes)
+      return false;
+  }
+  return true;
+}
+
 }  // namespace extensions