Resubmit of http://codereview.chromium.org/3476002/show but without the crashing bug.

BUG=none
TEST=none
Review URL: http://codereview.chromium.org/3618016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@61879 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 51 insertions, 9 deletions

diff --git a/webkit/fileapi/file_system_operation.cc b/webkit/fileapi/file_system_operation.cc
index 29336a8..29690b9 100644
--- a/webkit/fileapi/file_system_operation.cc
+++ b/webkit/fileapi/file_system_operation.cc
@@ -5,8 +5,9 @@
 #include "webkit/fileapi/file_system_operation.h"
 
 #include "base/time.h"
-#include "googleurl/src/gurl.h"
+#include "net/url_request/url_request_context.h"
 #include "webkit/fileapi/file_system_callback_dispatcher.h"
+#include "webkit/fileapi/file_writer_delegate.h"
 
 namespace fileapi {
 
@@ -24,6 +25,8 @@ FileSystemOperation::FileSystemOperation(
 }
 
 FileSystemOperation::~FileSystemOperation() {
+  if (file_writer_delegate_.get())
+    base::FileUtilProxy::Close(proxy_, file_writer_delegate_->file(), NULL);
 }
 
 void FileSystemOperation::CreateFile(const FilePath& path,
@@ -130,6 +133,7 @@ void FileSystemOperation::Remove(const FilePath& path, bool recursive) {
 }
 
 void FileSystemOperation::Write(
+    scoped_refptr<URLRequestContext> url_request_context,
     const FilePath& path,
     const GURL& blob_url,
     int64 offset) {
@@ -137,7 +141,28 @@ void FileSystemOperation::Write(
   DCHECK(kOperationNone == pending_operation_);
   pending_operation_ = kOperationWrite;
 #endif
-  NOTREACHED();
+  DCHECK(blob_url.is_valid());
+  file_writer_delegate_.reset(new FileWriterDelegate(this, offset));
+  blob_request_.reset(new URLRequest(blob_url, file_writer_delegate_.get()));
+  blob_request_->set_context(url_request_context);
+  base::FileUtilProxy::CreateOrOpen(
+      proxy_,
+      path,
+      base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_WRITE |
+          base::PLATFORM_FILE_ASYNC,
+      callback_factory_.NewCallback(
+          &FileSystemOperation::OnFileOpenedForWrite));
+}
+
+void FileSystemOperation::OnFileOpenedForWrite(
+    base::PlatformFileError rv,
+    base::PassPlatformFile file,
+    bool created) {
+  if (base::PLATFORM_FILE_OK != rv) {
+    dispatcher_->DidFail(rv);
+    return;
+  }
+  file_writer_delegate_->Start(file.ReleaseValue(), blob_request_.get());
 }
 
 void FileSystemOperation::Truncate(const FilePath& path, int64 length) {
@@ -166,15 +191,32 @@ void FileSystemOperation::TouchFile(const FilePath& path,
 // We can only get here on a write or truncate that's not yet completed.
 // We don't support cancelling any other operation at this time.
 void FileSystemOperation::Cancel(FileSystemOperation* cancel_operation) {
+  if (file_writer_delegate_.get()) {
 #ifndef NDEBUG
-  DCHECK(kOperationTruncate == pending_operation_);
-  // FIXME(ericu): Cancelling for writes coming soon.
+    DCHECK(kOperationWrite == pending_operation_);
 #endif
-  // We're cancelling a truncate operation, but we can't actually stop it
-  // since it's been proxied to another thread.  We need to save the
-  // cancel_operation so that when the truncate returns, it can see that it's
-  // been cancelled, report it, and report that the cancel has succeeded.
-  cancel_operation_ = cancel_operation;
+    // Writes are done without proxying through FileUtilProxy after the initial
+    // opening of the PlatformFile.  All state changes are done on this thread,
+    // so we're guaranteed to be able to shut down atomically.  We do need to
+    // check that the file has been opened [which means the blob_request_ has
+    // been created], so we know how much we need to do.
+    if (blob_request_.get())
+      // This halts any calls to file_writer_delegate_ from blob_request_.
+      blob_request_->Cancel();
+
+    // This deletes us, and by proxy deletes file_writer_delegate_ if any.
+    dispatcher_->DidFail(base::PLATFORM_FILE_ERROR_ABORT);
+    cancel_operation->dispatcher_->DidSucceed();
+  } else {
+#ifndef NDEBUG
+    DCHECK(kOperationTruncate == pending_operation_);
+#endif
+    // We're cancelling a truncate operation, but we can't actually stop it
+    // since it's been proxied to another thread.  We need to save the
+    // cancel_operation so that when the truncate returns, it can see that it's
+    // been cancelled, report it, and report that the cancel has succeeded.
+    cancel_operation_ = cancel_operation;
+  }
 }
 
 void FileSystemOperation::DidCreateFileExclusive(